IP-10 antibodies and their uses

ABSTRACT

The present invention provides isolated monoclonal antibodies, particularly human antibodies, that bind to IP-10 with high affinity, inhibit the binding of IP-10 to its receptor, inhibit IP-10-induced calcium flux and inhibit IP-10-induced cell migration. Nucleic acid molecules encoding the antibodies of the invention, expression vectors, host cells and methods for expressing the antibodies of the invention are also provided. Immunoconjugates, bispecific molecules and pharmaceutical compositions comprising the antibodies of the invention are also provided. The invention also provides methods for inhibiting IP-10 activity using the antibodies of the invention, including methods for treating various inflammatory and autoimmune diseases.

RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No. 13/478,876, filed May 23, 2012, which is a divisional of U.S. Pat. No. 8,258,266, issued Sep. 4, 2012, which is a continuation of U.S. application Ser. No. 11/009,731, filed Dec. 10, 2004 (abandoned), which is a non-provisional of U.S. application No. 60/529,180, filed Dec. 10, 2003, the contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

Interferon gamma inducible protein 10 (IP-10) (also known as CXCL10) is a 10 kDa chemokine that was originally identified based on expression of the IP-10 gene in cells treated with interferon gamma (IFN-gamma) (Luster, A. D. et al. (1985) Nature 315:672-676). IP-10 shows homology to proteins having chemotactic activity, such as platelet factor 4 and beta-thromoboglobulin, and to proteins having mitogenic activity, such as connective tissue-activating peptide III (Luster, A. D. et al. (1987) Proc. Natl. Acad. Sci. USA 84:2868-2871). IP-10 is secreted by a variety of cells, including endothelial cells, monocytes, fibroblasts, and keratinocytes, in response to IFN-gamma (Luster, A. D. and Ravetch, J. V. (1987) J. Exp. Med. 166:1084-1097). IP-10 also has been shown to be present in dermal macrophages and endothelial cells in delayed type hypersensitivity (DTH) responses in human skin (Kaplan, G. et al. (1987) J. Exp. Med. 166:1098-1108). Although originally identified based on its being induced by IFN-gamma, IP-10 also can be induced by IFN-alpha, for example in dendritic cells (Padovan, E. et al. (2002) J. Leukoc. Biol. 71:669-676). IP-10 expression can also be induced in cells of the central nervous system, such as astrocytes and microglia, by stimuli such as IFN-gamma, viruses and lipopolysaccharide (Vanguri, R. and Farber, J. M. (1994) J. Immunol. 152:1411-1418; Ren, L. Q. et al. (1998) Brain Res. Mol. Brain. Res. 59:256-263). The immunobiology of IP-10 is reviewed in Neville, L. F et al. (1997) Cytokine Growth Factor Rev. 8:207-219.

The receptor for IP-10 has been identified as CXCR3, a seven transmembrane receptor (Loetscher, M. et al. (1996) J. Exp. Med. 184:963-969). CXCR3 has been shown to be expressed on activated T lymphocytes but not on resting T lymphocytes, nor on B lymphocytes, monocytes or granulocytes (Loetscher, M. et al., supra). CXCR3 expression has been shown to be upregulated on NK cells by stimulation with TGF-beta 1 (Inngjerdingen, M. et al. (2001) Blood 97:367-375). Two other ligands for CXCR3 have also been identified: MIG (Loetscher, M. et al., supra) and ITAC (Cole, K. E. et al. (1998) J. Exp. Med. 187:2009-2021).

Binding of IP-10 to CXCR3 has been shown to mediate calcium mobilization and chemotaxis in activated T cells (Loetscher, M. et al., supra). Chemotaxis and intracellular calcium mobilization are also induced by IP-10 binding to CXCR3 on activated NK cells (Maghazachi, A. A. et al. (1997) FASEB J. 11:765-774). Within the thymus, IP-10 has been shown to be a chemoattractant for TCRαβ⁺ CD8⁺ T cells, TCRγδ⁺ T cells and NK-type cells (Romagnani, P. et al. (2001) Blood 97:601-607).

IP-10 or its receptor CXCR3 have been identified in a variety of different inflammatory and autoimmune conditions, including multiple sclerosis (see e.g., Sorensen, T. L. et al. (1999) J. Clin. Invest. 103:807-815), rheumatoid arthritis (see e.g., Patel, D. D. et al. (2001) Clin. Immunol. 98:39-45), ulcerative colitis (see e.g., Uguccioni, M. et al. (1999) Am. J. Pathol. 155:331-336), hepatitis (see e.g., Narumi, S. et al. (1997) J. Immunol. 158:5536-5544), spinal cord injury (see e.g., McTigue, D. M. et al. (1998) J. Neurosci. Res. 53:368-376; Gonzalez et al. 2003. Exp. Neurol. 184:456-463), systemic lupus erythematosus (see e.g., Narumi, S. et al. (2000) Cytokine 12:1561-1565), transplant rejection (see e.g., Zhang, Z. et al. (2002) J. Immunol. 168:3205-3212), Sjogren's syndrome (see e.g., Ogawa, N. et al. (2002) Arthritis Rheum. 46:2730-2741). Accordingly, therapeutic agents that inhibit the activity are desirable, in particular agents that are suitable for use in humans.

SUMMARY OF THE INVENTION

The present invention provides isolated monoclonal antibodies, in particular human monoclonal antibodies, that bind to IP-10 and that exhibit numerous desirable properties. These properties include high affinity binding to human IP-10, as well as cross-reactivity with rhesus monkey IP-10 but lacking substantial cross-reactivity with either human MIG, human ITAC or mouse IP-10. Furthermore, the antibodies inhibit the binding of IP-10 to its receptor, CXCR3, inhibit calcium flux induced by IP-10 in receptor-expressing cells and inhibit IP-10 induced cell migration (chemotaxis). Still further, antibodies of the invention have been shown to bind to IP-10 in brain sections of a human subject diagnosed with multiple sclerosis.

In preferred embodiments of the invention, the human IP-10 comprises a polypeptide having an amino acid sequence as set forth in SEQ ID NO: 121 [Genbank Acc. No. NP_001556]; the CXCR3 comprises a polypeptide having an amino acid sequence as set forth in SEQ ID NO: 122 [Genbank Acc. No. NP_001495]; the rhesus monkey IP-10 comprises a polypeptide having an amino acid sequence as set forth in SEQ ID NO: 123 [Genbank Acc. No. AAK95955]; the mouse IP-10 comprises a polypeptide having an amino acid sequence as set forth in SEQ ID NO: 124 [Genbank Acc. No. NP_067249]; the human MIG comprises a polypeptide having an amino acid sequence as set forth in SEQ ID NO: 125 [Genbank Acc. No. NP_002407]; and/or the human ITAC comprises a polypeptide having an amino acid sequence as set forth in SEQ ID NO: 126 [Genbank Acc. No. NP_005400].

In one embodiment, the invention provides an isolated monoclonal antibody, or an antigen-binding portion thereof, wherein the antibody specifically binds to IP-10 and comprises a heavy chain variable region that is the product of or derived from a human V_(H) germline gene selected from the group consisting of a human V_(H) 3-33 gene, a human V_(H) 3-30.3 gene, a human V_(H) 5-51 gene and a human V_(H) 4-61 gene. In another embodiment, the invention provides an isolated monoclonal antibody, or an antigen-binding portion thereof, wherein the antibody specifically binds to IP-10 and comprises a light chain variable region that is the product of or derived from a human V_(k) germline gene selected from the group consisting of a human V_(k) A27 gene, a human V_(k) L15 gene, a human V_(k) L6 gene and a human V_(k) L18 gene. In still another embodiment, the invention provides an isolated monoclonal antibody, or an antigen-binding portion thereof, wherein the antibody specifically binds to IP-10 and comprises:

-   -   (a) a heavy chain variable region that is the product of or         derived from a human V_(H) germline gene selected from the group         consisting of a human V_(H) 3-33 gene, a human V_(H) 3-30.3         gene, a human V_(H) 5-51 gene and a human V_(H) 4-61 gene; and     -   (b) a light chain variable region that is the product of or         derived from a human V_(k) germline gene selected from the group         consisting of a human V_(k) A27 gene, a human V_(k) L15 gene, a         human V_(k) L6 gene and a human V_(k) L18 gene.

In one embodiment, the invention provides an isolated monoclonal antibody, or an antigen-binding portion thereof, wherein the antibody comprises:

-   -   (a) a heavy chain variable region that is the product of or         derived from a human V_(H) 3-33 gene; and     -   (b) a light chain variable region that is the product of or         derived from a human Vk gene selected from the group consisting         of a human Vk A27, a human Vk L15 gene and a human Vk L6 gene,     -   wherein the antibody specifically binds to IP-10.

In another embodiment, the invention provides an isolated monoclonal antibody, or an antigen-binding portion thereof, wherein the antibody comprises:

-   -   (a) a heavy chain variable region that is the product of or         derived from a human V_(H) 3-30.3 gene; and     -   (b) a light chain variable region that is the product of or         derived from a human Vk L6 gene;     -   wherein the antibody specifically binds to IP-10.

In yet another embodiment, the invention provides an isolated monoclonal antibody, or an antigen-binding portion thereof, wherein the antibody comprises:

-   -   (a) a heavy chain variable region that is the product of or         derived from a human V_(H) 5-51 gene; and     -   (b) a light chain variable region that is the product of or         derived from a human Vk L18 gene;     -   wherein the antibody specifically binds to IP-10.

In yet another embodiment, the invention provides an isolated monoclonal antibody, or an antigen-binding portion thereof, wherein the antibody comprises:

-   -   (a) a heavy chain variable region that is the product of or         derived from a human V_(H) 4-61 gene; and     -   (b) a light chain variable region that is the product of or         derived from a human Vk A27 gene;     -   wherein the antibody specifically binds to IP-10.

In another aspect, the invention provides an isolated monoclonal antibody, or antigen binding portion thereof, comprising a heavy chain variable region comprising CDR1, CDR2, and CDR3 sequences and a light chain variable region comprising CDR1, CDR2, and CDR3 sequences, wherein:

-   -   (a) the heavy chain variable region CDR3 sequence comprises an         amino acid sequence selected from the group consisting of amino         acid sequences of SEQ ID NOs: 24-34, and conservative         modifications thereof,     -   (b) the light chain variable region CDR3 sequence comprises an         amino acid sequence selected from the group consisting of amino         acid sequence of SEQ ID NOs: 73-83, and conservative         modifications thereof,     -   (c) the antibody specifically binds to IP-10, and     -   (d) the antibody exhibits at least one of the following         functional properties:         -   (i) the antibody inhibits binding of IP-10 to CXCR3;         -   (ii) the antibody inhibits IP-10 induced calcium flux;         -   (iii) the antibody inhibits IP-10 induced cell migration;         -   (iv) the antibody cross-reacts with rhesus monkey IP-10;         -   (v) the antibody does not cross-react with mouse IP-10;         -   (vi) the antibody does not cross-react with human MIG;         -   (vii) the antibody does not cross-react with human ITAC.

In a preferred embodiment, the heavy chain variable region CDR2 sequence comprises an amino acid sequence selected from the group consisting of amino acid sequences of SEQ ID NOs: 13-23, and conservative modifications thereof; and the light chain variable region CDR2 sequence comprises an amino acid sequence selected from the group consisting of amino acid sequences of SEQ ID NOs: 62-72, and conservative modifications thereof. In another preferred embodiment, the heavy chain variable region CDR1 sequence comprises an amino acid sequence selected from the group consisting of amino acid sequences of SEQ ID NOs: 1-12, and conservative modifications thereof; and the light chain variable region CDR1 sequence comprises an amino acid sequence selected from the group consisting of amino acid sequences of SEQ ID NOs: 51-61, and conservative modifications thereof. The antibody can be, for example, a human antibody, a humanized antibody or a chimeric antibody.

In another aspect, the invention provides an isolated monoclonal antibody, or antigen binding portion thereof, comprising a heavy chain variable region and a light chain variable region, wherein:

-   -   (a) the heavy chain variable region comprises an amino acid         sequence that is at least 80% homologous to an amino acid         sequence selected from the group consisting of SEQ ID NOs:         35-46,     -   (b) the light chain variable region comprises an amino acid         sequence that is at least 80% homologous to an amino acid         sequence selected from the group consisting of SEQ ID NOs:84-94,     -   (c) the antibody specifically binds to IP-10, and     -   (d) the antibody exhibits at least one of the following         functional properties:         -   (i) the antibody inhibits binding of IP-10 to CXCR3;         -   (ii) the antibody inhibits IP-10 induced calcium flux;         -   (iii) the antibody inhibits IP-10 induced cell migration;         -   (iv) the antibody cross-reacts with rhesus monkey IP-10;         -   (v) the antibody does not cross-react with mouse IP-10;         -   (vi) the antibody does not cross-react with human MIG;         -   (vii) the antibody does not cross-react with human ITAC.

The antibody can be, for example, a human antibody, a humanized antibody or a chimeric antibody.

In preferred embodiments of the invention, the isolated monoclonal antibody, or antigen binding portion thereof comprises:

(a) a heavy chain variable region CDR1 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 1-12;

(b) a heavy chain variable region CDR2 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 13-23;

(c) a heavy chain variable region CDR3 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 24-34;

(d) a light chain variable region CDR1 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 51-61;

(e) a light chain variable region CDR2 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 62-72; and

(f) a light chain variable region CDR3 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 73-83;

wherein the antibody specifically binds IP-10.

In other preferred embodiments, the invention provides an isolated monoclonal antibody, or antigen binding portion thereof comprising:

(a) a heavy chain variable region comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 35-46; and

(b) a light chain variable region comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 84-94;

wherein the antibody specifically binds IP-10.

In another aspect of the invention, antibodies, or antigen-binding portions thereof, are provided that compete for binding to IP-10 with any of the aforementioned antibodies.

The antibodies of the invention can be, for example, full-length antibodies, for example of an IgG1 or IgG4 isotype. Alternatively, the antibodies can be antibody fragments, such as Fab or Fab′2 fragments, or single chain antibodies.

The invention also provides an immunoconjugate comprising an antibody of the invention, or antigen-binding portion thereof, linked to a therapeutic agent, such as a cytotoxin or a radioactive isotope. The invention also provides a bispecific molecule comprising an antibody, or antigen-binding portion thereof, of the invention, linked to a second functional moiety having a different binding specificity than said antibody, or antigen binding portion thereof.

Compositions comprising an antibody, or antigen-binding portion thereof, or immunoconjugate or bispecific molecule of the invention and a pharmaceutically acceptable carrier are also provided.

Nucleic acid molecules encoding the antibodies, or antigen-binding portions thereof, of the invention are also encompassed by the invention, as well as expression vectors comprising such nucleic acids and host cells comprising such expression vectors. Moreover, the invention provides a transgenic mouse comprising human immunoglobulin heavy and light chain transgenes, wherein the mouse expresses an antibody of the invention, as well as hybridomas prepared from such a mouse, wherein the hybridoma produces the antibody of the invention.

In another aspect, the invention provides a method of inhibiting an inflammatory or autoimmune response mediated by activated T cells or NK cells comprising contacting the T cells or NK cells with the antibody, or antigen-binding portion thereof, of the invention, such that the inflammatory or autoimmune response is inhibited.

In yet another aspect, the invention provides a method of treating an inflammatory or autoimmune disease in a subject in need of treatment comprising administering to the subject the antibody, or antigen-binding portion thereof, of the invention, such that the inflammatory or autoimmune disease in the subject is treated. The disease can be, for example, multiple sclerosis, rheumatoid arthritis, inflammatory bowel disease (e.g., ulcerative colitis, Crohn's disease), systemic lupus erythematosus, Type I diabetes, inflammatory skin disorders (e.g., psoriasis, lichen planus), autoimmune thyroid disease (e.g., Graves' disease, Hashimoto's thyroiditis), Sjogren's syndrome, pulmonary inflammation (e.g., asthma, chronic obstructive pulmonary disease, pulmonary sarcoidosis, lymphocytic alveolitis), transplant rejection, spinal cord injury, brain injury (e.g., stroke), neurodegenerative diseases (e.g., Alzheimer's disease, Parkinson's disease), gingivitis, gene therapy-induced inflammation, diseases of angiogenesis, inflammatory kidney disease (e.g., IgA nephropathy, memranoproliferative glomerulonephritis, rapidly progressive glomerulonephritis) and atherosclerosis.

In still another aspect, the invention provides a method of treating a viral or bacterial infection involving unwanted IP-10 activity in a subject in need of treatment comprising administering to the subject the antibody, or antigen-binding portion thereof, of the invention, such that the viral or bacterial infection in the subject is treated. For example, the antibodies can be used to treat viral meningitis, viral encephalitis or bacterial meningitis. Viral infection to be treated by the method of the invention can be mediated by, for example, human immunodeficiency virus (HIV), hepatitis C virus (HCV), herpes simplex virus type I (HSV-1) or the Severe Acute Respiratory Syndrome (SARS) virus.

The invention also provides methods for making “second generation” anti-IP-10 antibodies based on the sequences of the anti-IP-10 antibodies provided herein. For example, the invention provides a method for preparing an anti-IP-10 antibody comprising:

(a) providing: (i) a heavy chain variable region antibody sequence comprising a CDR1 sequence selected from the group consisting of SEQ ID NOs: 1-12, a CDR2 sequence selected from the group consisting of SEQ ID NOs: 13-23 and/or a CDR3 sequence selected from the group consisting of SEQ ID NOs: 24-34; and (ii) a light chain variable region antibody sequence comprising a CDR1 sequence selected from the group consisting of SEQ ID NOs: 51-61, a CDR2 sequence selected from the group consisting of SEQ ID NOs: 62-72 and/or a CDR3 sequence selected from the group consisting of SEQ ID NOs: 73-83;

(b) altering at least one amino acid residue within the heavy chain variable region antibody sequence and/or the light chain variable region antibody sequence to create at least one altered antibody sequence; and

(c) expressing the altered antibody sequence as a protein.

Other features and advantages of the instant invention will be apparent from the following detailed description and examples which should not be construed as limiting. The contents of all references, Genbank entries, patents and published patent applications cited throughout this application are expressly incorporated herein by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows the nucleotide sequence (SEQ ID NO: 99) and amino acid sequence (SEQ ID NO: 35) of the heavy chain variable region of the 1D4 human monoclonal antibody. The CDR1 (SEQ ID NO: 1), CDR2 (SEQ ID NO: 13) and CDR3 (SEQ ID NO: 24) regions are delineated and the V, D and J germline derivations are indicated.

FIG. 1B shows the nucleotide sequence (SEQ ID NO: 110) and amino acid sequence (SEQ ID NO: 84) of the light chain variable region of the 1D4 human monoclonal antibody. The CDR1 (SEQ ID NO: 51), CDR2 (SEQ ID NO: 62) and CDR3 (SEQ ID NO: 73) regions are delineated and the V and J germline derivations are indicated.

FIG. 2A shows the nucleotide sequence (SEQ ID NO: 100) and amino acid sequence (SEQ ID NO: 36) of the heavy chain variable region of the 1E1 human monoclonal antibody. The CDR1 (SEQ ID NO: 2), CDR2 (SEQ ID NO: 14) and CDR3 (SEQ ID NO: 25) regions are delineated and the V and J germline derivations are indicated.

FIG. 2B shows the nucleotide sequence (SEQ ID NO: 111) and amino acid sequence (SEQ ID NO: 85) of the light chain variable region of the 1E1 human monoclonal antibody. The CDR1 (SEQ ID NO: 52), CDR2 (SEQ ID NO: 63) and CDR3 (SEQ ID NO: 74) regions are delineated and the V and J germline derivations are indicated.

FIG. 3A shows the nucleotide sequence (SEQ ID NO: 101) and amino acid sequence (SEQ ID NO: 37) of the heavy chain variable region of the 2G1 human monoclonal antibody. The CDR1 (SEQ ID NO: 3), CDR2 (SEQ ID NO: 15) and CDR3 (SEQ ID NO: 26) regions are delineated and the V and J germline derivations are indicated.

FIG. 3B shows the nucleotide sequence (SEQ ID NO: 112) and amino acid sequence (SEQ ID NO: 86) of the light chain variable region of the 2G1 human monoclonal antibody. The CDR1 (SEQ ID NO: 53), CDR2 (SEQ ID NO: 64) and CDR3 (SEQ ID NO: 75) regions are delineated and the V and J germline derivations are indicated.

FIG. 4A shows the nucleotide sequence (SEQ ID NO: 102) and amino acid sequence (SEQ ID NO: 38) of the heavy chain variable region of the 3C4 human monoclonal antibody. The CDR1 (SEQ ID NO: 4), CDR2 (SEQ ID NO: 16) and CDR3 (SEQ ID NO: 27) regions are delineated and the V, D and J germline derivations are indicated.

FIG. 4B shows the nucleotide sequence (SEQ ID NO: 113) and amino acid sequence (SEQ ID NO: 87) of the light chain variable region of the 3C4 human monoclonal antibody. The CDR1 (SEQ ID NO: 54), CDR2 (SEQ ID NO: 65) and CDR3 (SEQ ID NO: 76) regions are delineated and the V and J germline derivations are indicated.

FIG. 5A shows the nucleotide sequence (SEQ ID NO: 103) and amino acid sequence (SEQ ID NO: 39) of the heavy chain variable region of the 6A5 human monoclonal antibody. The CDR1 (SEQ ID NO: 5), CDR2 (SEQ ID NO: 17) and CDR3 (SEQ ID NO: 28) regions are delineated and the V, D and J germline derivations are indicated.

FIG. 5B shows the nucleotide sequence (SEQ ID NO: 114) and amino acid sequence (SEQ ID NO: 88) of the light chain variable region of the 6A5 human monoclonal antibody. The CDR1 (SEQ ID NO: 55), CDR2 (SEQ ID NO: 66) and CDR3 (SEQ ID NO: 77) regions are delineated and the V and J germline derivations are indicated.

FIG. 6A shows the nucleotide sequence (SEQ ID NO: 104) and amino acid sequence (SEQ ID NO: 40) of the heavy chain variable region of the 6A8 human monoclonal antibody. The CDR1 (SEQ ID NO: 6), CDR2 (SEQ ID NO: 18) and CDR3 (SEQ ID NO: 29) regions are delineated and the V and J germline derivations are indicated.

FIG. 6B shows the nucleotide sequence (SEQ ID NO: 115) and amino acid sequence (SEQ ID NO: 89) of the light chain variable region of the 6A8 human monoclonal antibody. The CDR1 (SEQ ID NO: 56), CDR2 (SEQ ID NO: 67) and CDR3 (SEQ ID NO: 78) regions are delineated and the V and J germline derivations are indicated.

FIG. 7A shows the nucleotide sequence (SEQ ID NO: 105) and amino acid sequence (SEQ ID NO: 41) of the heavy chain variable region of the 6B10 human monoclonal antibody. The CDR1 (SEQ ID NO: 7), CDR2 (SEQ ID NO: 19) and CDR3 (SEQ ID NO: 30) regions are delineated and the V, D and J germline derivations are indicated.

FIG. 7B shows the nucleotide sequence (SEQ ID NO: 116) and amino acid sequence (SEQ ID NO: 90) of the light chain variable region of the 6B10 human monoclonal antibody. The CDR1 (SEQ ID NO: 57), CDR2 (SEQ ID NO: 68) and CDR3 (SEQ ID NO: 79) regions are delineated and the V and J germline derivations are indicated.

FIG. 8A shows the nucleotide sequence (SEQ ID NO: 106) and amino acid sequence (SEQ ID NO: 42) of the heavy chain variable region of the 7C10 human monoclonal antibody. The CDR1 (SEQ ID NO: 8), CDR2 (SEQ ID NO: 20) and CDR3 (SEQ ID NO: 31) regions are delineated and the V, D and J germline derivations are indicated.

FIG. 8B shows the nucleotide sequence (SEQ ID NO: 117) and amino acid sequence (SEQ ID NO: 91) of the light chain variable region of the 7C10 human monoclonal antibody. The CDR1 (SEQ ID NO: 58), CDR2 (SEQ ID NO: 69) and CDR3 (SEQ ID NO: 80) regions are delineated and the V and J germline derivations are indicated.

FIG. 9A shows the nucleotide sequence (SEQ ID NO: 107) and amino acid sequence (SEQ ID NO: 43) of the heavy chain variable region of the 8F6 human monoclonal antibody. The CDR1 (SEQ ID NO: 9), CDR2 (SEQ ID NO: 21) and CDR3 (SEQ ID NO: 32) regions are delineated and the V, D and J germline derivations are indicated.

FIG. 9B shows the nucleotide sequence (SEQ ID NO: 118) and amino acid sequence (SEQ ID NO: 92) of the light chain variable region of the 8F6 human monoclonal antibody. The CDR1 (SEQ ID NO: 59), CDR2 (SEQ ID NO: 70) and CDR3 (SEQ ID NO: 81) regions are delineated and the V and J germline derivations are indicated.

FIG. 10A shows the nucleotide sequence (SEQ ID NO: 108) and amino acid sequence (SEQ ID NO: 44) of the heavy chain variable region of the 10A12 human monoclonal antibody. The CDR1 (SEQ ID NO: 10), CDR2 (SEQ ID NO: 22) and CDR3 (SEQ ID NO: 33) regions are delineated and the V and J germline derivations are indicated. Alternatively, amino acid residue 32 within CDR1 can be mutated from cysteine to serine (SEQ ID NO: 11), leading to the VH sequence of SEQ ID NO: 45.

FIG. 10B shows the nucleotide sequence (SEQ ID NO: 119) and amino acid sequence (SEQ ID NO: 93) of the light chain variable region of the 10A12 human monoclonal antibody. The CDR1 (SEQ ID NO: 60), CDR2 (SEQ ID NO: 71) and CDR3 (SEQ ID NO: 82) regions are delineated and the V and J germline derivations are indicated.

FIG. 11A shows the nucleotide sequence (SEQ ID NO: 109) and amino acid sequence (SEQ ID NO: 46) of the heavy chain variable region of the 13C4 human monoclonal antibody. The CDR1 (SEQ ID NO: 12), CDR2 (SEQ ID NO: 23) and CDR3 (SEQ ID NO: 34) regions are delineated and the V, D and J germline derivations are indicated.

FIG. 11B shows the nucleotide sequence (SEQ ID NO: 120) and amino acid sequence (SEQ ID NO: 94) of the light chain variable region of the 13C4 human monoclonal antibody. The CDR1 (SEQ ID NO: 61), CDR2 (SEQ ID NO: 72) and CDR3 (SEQ ID NO: 83) regions are delineated and the V and J germline derivations are indicated.

FIG. 12 shows the alignment of the amino acid sequence of the heavy chain variable region of 1D4, 1E1, 2G1, 6A5, 6A8, 7C10 and 10A12 with the human germline V_(H) 3-33 amino acid sequence (SEQ ID NO: 47).

FIG. 13 shows the alignment of the amino acid sequence of the heavy chain variable region of 6B10 and 8F6 with the human germline V_(H) 3-30.3 amino acid sequence (SEQ ID NO: 48).

FIG. 14 shows the alignment of the amino acid sequence of the heavy chain variable region of 3C4 with the human germline V_(H) 5-51 amino acid sequence (SEQ ID NO: 49).

FIG. 15 shows the alignment of the amino acid sequence of the heavy chain variable region of 13C4 with the human germline V_(H) 4-61 amino acid sequence (SEQ ID NO: 50).

FIG. 16 shows the alignment of the amino acid sequence of the light chain variable region of 1D4, 2G1, 6A5, 6A8, 10A12 and 13C4 with the human germline V_(k) A27 amino acid sequence (SEQ ID NO: 95).

FIG. 17 shows the alignment of the amino acid sequence of the light chain variable region of 1E1, 6B10 and 8F6 with the human germline V_(k) L6 amino acid sequence (SEQ ID NO: 96).

FIG. 18 shows the alignment of the amino acid sequence of the light chain variable region of 3C4 with the human germline V_(k) L18 amino acid sequence (SEQ ID NO: 97).

FIG. 19 shows the alignment of the amino acid sequence of the light chain variable region of 7C10 with the human germline V_(k) L15 amino acid sequence (SEQ ID NO: 98).

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to isolated monoclonal antibodies, particularly human monoclonal antibodies, that bind specifically to IP-10 and that inhibit functional properties of IP-10. In certain embodiments, the antibodies of the invention are derived from particular heavy and light chain germline sequences and/or comprise particular structural features such as CDR regions comprising particular amino acid sequences. The invention provides isolated antibodies, methods of making such antibodies, immunoconjugates and bispecific molecules comprising such antibodies and pharmaceutical compositions containing the antibodies, immunconjugates or bispecific molecules of the invention. The invention also relates to methods of using the antibodies to inhibit inflammatory or autoimmune responses, for example in the treatment of various inflammatory or autoimmune diseases, as well as methods of treating viral infections involving unwanted IP-10 activity.

In order that the present invention may be more readily understood, certain terms are first defined. Additional definitions are set forth throughout the detailed description.

The terms “interferon gamma inducible protein 10” “IP-10,” and “CXCL10” are used interchangeably, and include variants, isoforms and species homologs of human IP-10. Accordingly, human antibodies of the invention may, in certain cases, cross-react with IP-10 from species other than human. In other cases, the antibodies may be completely specific for human IP-10 and may not exhibit species or other types of cross-reactivity. The complete amino acid sequence of human IP-10 has Genbank accession number NP_001556 (SEQ ID NO: 121). The complete amino acid sequence of rhesus monkey IP-10 has Genbank accession number AAK95955 (SEQ ID NO: 123). The complete amino acid sequence of mouse IP-10 has Genbank accession number NP_067249 (SEQ ID NO: 124).

The term “CXCR3” refers to the receptor for IP-10 (CXCL10). The complete amino acid sequence of human CXCR3 has Genbank accession number NP_001495 (SEQ ID NO: 122).

The term “MIG” refers to a ligand for CXCR3, also know as monokine induced by gamma interferon, that is distinct from IP-10. The complete amino acid sequence of human MIG has Genbank accession number NP_002407 (SEQ ID NO: 125).

The term “ITAC” refers to a ligand for CXCR3, also known as interferon-inducible T cell alpha chemoattractant, that is distinct from IP-10. The complete amino acid sequence of human ITAC has Genbank accession number NP_005400 (SEQ ID NO: 126).

The term “immune response” refers to the action of, for example, lymphocytes, antigen presenting cells, phagocytic cells, granulocytes, and soluble macromolecules produced by the above cells or the liver (including antibodies, cytokines, and complement) that results in selective damage to, destruction of, or elimination from the human body of invading pathogens, cells or tissues infected with pathogens, cancerous cells, or, in cases of autoimmunity or pathological inflammation, normal human cells or tissues.

A “signal transduction pathway” refers to the biochemical relationship between a variety of signal transduction molecules that play a role in the transmission of a signal from one portion of a cell to another portion of a cell. As used herein, the phrase “cell surface receptor” includes, for example, molecules and complexes of molecules capable of receiving a signal and the transmission of such a signal across the plasma membrane of a cell. An example of a “cell surface receptor” of the present invention is the CXCR3 receptor to which the IP-10 molecule binds.

The term “antibody” as referred to herein includes whole antibodies and any antigen binding fragment (i.e., “antigen-binding portion”) or single chains thereof. An “antibody” refers to a glycoprotein comprising at least two heavy (H) chains and two light (L) chains inter-connected by disulfide bonds, or an antigen binding portion thereof. Each heavy chain is comprised of a heavy chain variable region (abbreviated herein as V_(H)) and a heavy chain constant region. The heavy chain constant region is comprised of three domains, C_(H1), C_(H2) and C_(H3). Each light chain is comprised of a light chain variable region (abbreviated herein as V_(L)) and a light chain constant region. The light chain constant region is comprised of one domain, C_(L). The V_(H) and V_(L) regions can be further subdivided into regions of hypervariability, termed complementarity determining regions (CDR), interspersed with regions that are more conserved, termed framework regions (FR). Each V_(H) and V_(L) is composed of three CDRs and four FRs, arranged from amino-terminus to carboxy-terminus in the following order: FR1, CDR1, FR2, CDR2, FR3, CDR3, FR4. The variable regions of the heavy and light chains contain a binding domain that interacts with an antigen. The constant regions of the antibodies may mediate the binding of the immunoglobulin to host tissues or factors, including various cells of the immune system (e.g., effector cells) and the first component (Clq) of the classical complement system.

The term “antigen-binding portion” of an antibody (or simply “antibody portion”), as used herein, refers to one or more fragments of an antibody that retain the ability to specifically bind to an antigen (e.g., IP-10). It has been shown that the antigen-binding function of an antibody can be performed by fragments of a full-length antibody. Examples of binding fragments encompassed within the term “antigen-binding portion” of an antibody include (i) a Fab fragment, a monovalent fragment consisting of the V_(L), V_(H), C_(L) and C_(H1) domains; (ii) a F(ab′)₂ fragment, a bivalent fragment comprising two Fab fragments linked by a disulfide bridge at the hinge region; (iii) a Fd fragment consisting of the V_(H) and C_(H1) domains; (iv) a Fv fragment consisting of the V_(L) and V_(H) domains of a single arm of an antibody, (v) a dAb fragment (Ward et al., (1989) Nature 341:544-546), which consists of a V_(H) domain; and (vi) an isolated complementarity determining region (CDR). Furthermore, although the two domains of the Fv fragment, V_(L) and V_(H), are coded for by separate genes, they can be joined, using recombinant methods, by a synthetic linker that enables them to be made as a single protein chain in which the V_(L) and V_(H) regions pair to form monovalent molecules (known as single chain Fv (scFv); see e.g., Bird et al. (1988) Science 242:423-426; and Huston et al. (1988) Proc. Natl. Acad. Sci. USA 85:5879-5883). Such single chain antibodies are also intended to be encompassed within the term “antigen-binding portion” of an antibody. These antibody fragments are obtained using conventional techniques known to those with skill in the art, and the fragments are screened for utility in the same manner as are intact antibodies.

An “isolated antibody”, as used herein, is intended to refer to an antibody that is substantially free of other antibodies having different antigenic specificities (e.g., an isolated antibody that specifically binds IP-10 is substantially free of antibodies that specifically bind antigens other than IP-10). An isolated antibody that specifically binds IP-10 may, however, have cross-reactivity to other antigens, such as IP-10 molecules from other species. Moreover, an isolated antibody may be substantially free of other cellular material and/or chemicals.

The terms “monoclonal antibody” or “monoclonal antibody composition” as used herein refer to a preparation of antibody molecules of single molecular composition. A monoclonal antibody composition displays a single binding specificity and affinity for a particular epitope.

The term “human antibody”, as used herein, is intended to include antibodies having variable regions in which both the framework and CDR regions are derived from human germline immunoglobulin sequences. Furthermore, if the antibody contains a constant region, the constant region also is derived from human germline immunoglobulin sequences. The human antibodies of the invention may include amino acid residues not encoded by human germline immunoglobulin sequences (e.g., mutations introduced by random or site-specific mutagenesis in vitro or by somatic mutation in vivo). However, the term “human antibody”, as used herein, is not intended to include antibodies in which CDR sequences derived from the germline of another mammalian species, such as a mouse, have been grafted onto human framework sequences.

The term “human monoclonal antibody” refers to antibodies displaying a single binding specificity which have variable regions in which both the framework and CDR regions are derived from human germline immunoglobulin sequences. In one embodiment, the human monoclonal antibodies are produced by a hybridoma which includes a B cell obtained from a transgenic nonhuman animal, e.g., a transgenic mouse, having a genome comprising a human heavy chain transgene and a light chain transgene fused to an immortalized cell.

The term “recombinant human antibody”, as used herein, includes all human antibodies that are prepared, expressed, created or isolated by recombinant means, such as (a) antibodies isolated from an animal (e.g., a mouse) that is transgenic or transchromosomal for human immunoglobulin genes or a hybridoma prepared therefrom (described further below), (b) antibodies isolated from a host cell transformed to express the human antibody, e.g., from a transfectoma, (c) antibodies isolated from a recombinant, combinatorial human antibody library, and (d) antibodies prepared, expressed, created or isolated by any other means that involve splicing of human immunoglobulin gene sequences to other DNA sequences. Such recombinant human antibodies have variable regions in which the framework and CDR regions are derived from human germline immunoglobulin sequences. In certain embodiments, however, such recombinant human antibodies can be subjected to in vitro mutagenesis (or, when an animal transgenic for human Ig sequences is used, in vivo somatic mutagenesis) and thus the amino acid sequences of the V_(H) and V_(L) regions of the recombinant antibodies are sequences that, while derived from and related to human germline V_(H) and V_(L) sequences, may not naturally exist within the human antibody germline repertoire in vivo.

As used herein, “isotype” refers to the antibody class (e.g., IgM or IgG1) that is encoded by the heavy chain constant region genes.

The phrases “an antibody recognizing an antigen” and “an antibody specific for an antigen” are used interchangeably herein with the term “an antibody which binds specifically to an antigen.”

As used herein, an antibody that “specifically binds to human IP-10” is intended to refer to an antibody that binds to human IP-10 with a K_(D) of 5×10⁻⁹ M or less, more preferably 2×10⁻⁹ M or less, and even more preferably 1×10⁻¹⁰ M or less. An antibody that “cross-reacts with rhesus monkey IP-10” is intended to refer to an antibody that binds to rhesus monkey IP-10 with a K_(D) of 0.5×10⁻⁸M or less, more preferably 5×10⁻⁹ M or less, and even more preferably 2×10⁻⁹ M or less. An antibody that “does not cross-react with mouse IP-10” or “does not cross-react with human MIG” or “does not cross-react with human ITAC” is intended to refer to an antibody that binds to mouse IP-10, human MIG or human ITAC with a K_(D) of 1.5×10⁻⁸ M or greater, more preferably a K_(D) of 5−10×10⁻⁸ M or greater and even more preferably 1×10⁻⁷ M or greater. In certain embodiments, such antibodies that do not cross-react with mouse IP-10, human MIG and/or human ITAC exhibit essentially undetectable binding against these proteins in standard binding assays.

As used herein, an antibody that “inhibits binding of IP-10 to CXCR3” is intended to refer to an antibody that inhibits IP-10 binding to CXCR3 with a K_(i) of 1 nM or less, more preferably 0.75 nM or less, even more preferably 0.5 nM or less and even more preferably 0.25 nM or less.

As used herein, an antibody that “inhibits IP-10 induced calcium flux” is intended to refer to an antibody that inhibits IP-10 induced calcium flux with a IC₅₀ of 10 nM or less, more preferably 7.5 nM or less, even more preferably 5 nM or less and even more preferably 2.5 nM or less.

As used herein, an antibody that “inhibits IP-10 induced cell migration” is intended to refer to an antibody that inhibits human IP-10 induced cell migration with a IC₅₀ of 2 μg/ml or less, more preferably 1 μg/ml or less, even more preferably 0.5 μg/ml or less and even more preferably 0.25 μg/ml or less.

The term “K_(assoc)” or “K_(a)”, as used herein, is intended to refer to the association rate of a particular antibody-antigen interaction, whereas the term “K_(dis)” or “K_(d),” as used herein, is intended to refer to the dissociation rate of a particular antibody-antigen interaction. The term “K_(D)”, as used herein, is intended to refer to the dissociation constant, which is obtained from the ratio of K_(d) to K_(a) (i.e., K_(d)/K_(a)) and is expressed as a molar concentration (M). K_(D) values for antibodies can be determined using methods well established in the art. A preferred method for determining the K_(D) of an antibody is by using surface plasmon resonance, preferably using a biosensor system such as a Biacore® system.

As used herein, the term “high affinity” for an IgG antibody refers to an antibody having a K_(D) of 10⁻⁸ M or less, more preferably 10⁻⁹ M or less and even more preferably 10⁻¹⁰ M or less for a target antigen. However, “high affinity” binding can vary for other antibody isotypes. For example, “high affinity” binding for an IgM isotype refers to an antibody having a K_(D) of 10⁻⁷ M or less, more preferably 10⁻⁸ M or less.

As used herein, the term “subject” includes any human or nonhuman animal. The term “nonhuman animal” includes all vertebrates, e.g., mammals and non-mammals, such as nonhuman primates, sheep, dogs, cats, horses, cows chickens, amphibians, reptiles, etc.

Various aspects of the invention are described in further detail in the following subsections.

Anti-IP-10 Antibodies

The antibodies of the invention are characterized by particular functional features or properties of the antibodies. For example, the antibodies bind specifically to human IP-10. Additionally, the antibodies may cross react with IP-10 from one or more non-human primates, such as rhesus monkey. Preferably, the antibodies do not cross react with mouse IP-10. Moreover, although MIG and ITAC are also ligands for the CXCR3 receptor, the antibodies of the invention preferably do not cross react with human MIG or human ITAC.

Preferably, an antibody of the invention binds to IP-10 with high affinity, for example with a K_(D) of 10⁻⁸M or less or 10⁻⁹ M or less or even 10⁻¹⁰ M or less.

Furthermore, the antibodies of the invention are capable of inhibiting one or more functional activities of IP-10. For example, in one embodiment, the antibodies inhibit the binding of IP-10 to CXCR3. In another embodiment, the antibodies inhibit IP-10 induced calcium flux. In yet another embodiment, the antibodies inhibit IP-10 induced cell migration (chemotaxis).

Standard assays to evaluate the binding ability of the antibodies toward IP-10 of various species and/or MIG or ITAC are known in the art, including for example, ELISAs, Western blots and RIAs. Suitable assays are described in detail in the Examples. The binding kinetics (e.g., binding affinity) of the antibodies also can be assessed by standard assays known in the art, such as by Biacore analysis. Assays to evaluate the effects of the antibodies on functional properties of IP-10 (e.g., receptor binding, calcium flux, chemotaxis) are described in further detail in the Examples.

Accordingly, an antibody that “inhibits” one or more of these IP-10 functional properties (e.g., biochemical, immunochemical, cellular, physiological or other biological activities, or the like) as determined according to methodologies known to the art and described herein, will be understood to relate to a statistically significant decrease in the particular activity relative to that seen in the absence of the antibody (e.g., or when a control antibody of irrelevant specificity is present). Preferably an antibody that inhibits an IP-10 activity effects such a statistically significant decrease by at least 10% of the measured parameter, more preferably by at least 20%, 30%, 40%, 50%, 60%, 70%, 80% or 90%, and in certain preferred embodiments an antibody of the invention may inhibit greater than 92%, 94%, 95%, 97%, 98% or 99% of an IP-10 functional activity.

Monoclonal Antibodies 1D4, 1E1, 2G1, 3C4, 6A5, 6A8, 6B10, 7C10, 8F6, 10A12 and 13C4

Preferred antibodies of the invention are the human monoclonal antibodies 1D4, 1E1, 2G1, 3C4, 6A5, 6A8, 6B10, 7C10, 8F6, 10A12 and 13C4, isolated and structurally characterized as described in Examples 1 and 2. Another preferred antibody is 10A12S, in which amino acid residue 32 of the heavy chain of 10A12 (within V_(H) CDR1) has been mutated from a cysteine to a serine. The V_(H) amino acid sequences of 1E1, 2G1, 3C4, 6A5, 6A8, 6B10, 7C10, 8F6, 10A12, 10A12S and 13C4 are shown in SEQ ID NOs: 35-46, respectively. The V_(L) amino acid sequences of 1E1, 2G1, 3C4, 6A5, 6A8, 6B10, 7C10, 8F6, 10A12 and 13C4 are shown in SEQ ID NOs: 84-94, respectively.

Given that each of these antibodies can bind to IP-10, the V_(H) and V_(L) sequences can be “mixed and matched” to create other anti-IP-10 binding molecules of the invention. IP-10 binding of such “mixed and matched” antibodies can be tested using the binding assays described above and in the Examples (e.g., ELISAs). Preferably, when V_(H) and V_(L) chains are mixed and matched, a V_(H) sequence from a particular V_(H)/V_(L) pairing is replaced with a structurally similar V_(H) sequence. Likewise, preferably a V_(L) sequence from a particular V_(H)/V_(L) pairing is replaced with a structurally similar V_(L) sequence. For example, the V_(H) and V_(L) sequences of 1D4, 2G1, 6A5, 6A8, 10A12 or 10A125 are particularly amenable for mixing and matching, since these antibodies use V_(H) and V_(L) sequences derived from the same germline sequences (VH 3-33 and Vk A27) and thus they exhibit structural similarity. Likewise, the V_(H) and V_(L) sequences of 6B10 and 8F6 also are particularly amenable to mixing and matching, since they too use V_(H) and V_(L) sequences derived from the same germline sequences (VH 3-30.3 and Vk L6) and thus they exhibit structural similarity. Alternatively, for example, the V_(H) sequence of 1D4, 2G1, 6A5, 6A8, 10A12 or 10A12S can be paired with the V_(L) of 13C4, since the V_(H) sequences of 1D4, 2G1, 6A5, 6A8, 10A12 and 10A12S originally paired with a V_(L) sequence of germline Vk A27 and the V_(L) sequence of 13C4 also is derived from germline Vk A27. Likewise, the V_(L) sequence of 7C10 or 1E1 can be paired with the V_(H) of 1D4, 2G1, 6A5, 6A8, 10A12 or 10A12S, since the V_(L) sequences of 7C10 and 1E1 originally paired with a V_(H) sequence of germline VH 3-33 and the V_(H) sequences of 1D4, 2G1, 6A5, 6A8, 10A12 and 10A12S also are derived from germline VH 3-33. It will be readily apparent to the ordinarily skilled artisan that other V_(H)/V_(L) pairing of structurally similar sequences can be created from the V_(H) and V_(L) sequences disclosed herein for monoclonal antibodies antibodies 1D4, 1E1, 2G1, 3C4, 6A5, 6A8, 6B10, 7C10, 8F6, 10A12 and 13C4.

Accordingly, in one aspect, the invention provides an isolated monoclonal antibody, or antigen binding portion thereof comprising:

(a) a heavy chain variable region comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 35-46; and

(b) a light chain variable region comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 84-94;

wherein the antibody specifically binds IP-10.

Preferred heavy and light chain combinations include:

(a) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 35; and (b) a light chain variable region comprising the amino acid sequence of SEQ ID NO: 84; or

(a) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 36; and (b) a light chain variable region comprising the amino acid sequence of SEQ ID NO: 85; or

(a) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 37; and (b) a light chain variable region comprising the amino acid sequence of SEQ ID NO: 86; or

(a) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 38; and (b) a light chain variable region comprising the amino acid sequence of SEQ ID NO: 87; or

(a) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 39; and (b) a light chain variable region comprising the amino acid sequence of SEQ ID NO: 88; or

(a) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 40; and (b) a light chain variable region comprising the amino acid sequence of SEQ ID NO: 89; or

(a) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 41; and (b) a light chain variable region comprising the amino acid sequence of SEQ ID NO: 90; or

(a) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 42; and (b) a light chain variable region comprising the amino acid sequence of SEQ ID NO: 91; or

(a) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 43; and (b) a light chain variable region comprising the amino acid sequence of SEQ ID NO: 92; or

(a) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 44 or 45; and (b) a light chain variable region comprising the amino acid sequence of SEQ ID NO: 93; or

(a) a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 46; and (b) a light chain variable region comprising the amino acid sequence of SEQ ID NO: 94.

In another aspect, the invention provides antibodies that comprise the heavy chain and light chain CDR1s, CDR2s and CDR3s of 1D4, 1E1, 2G1, 3C4, 6A5, 6A8, 6B10, 7C10, 8F6, 10A12, 10A12S and 13C4, or combinations thereof. The amino acid sequences of the V_(H) CDR1s of 1D4, 1E1, 2G1, 3C4, 6A5, 6A8, 6B10, 7C10, 8F6, 10A12, 10A12S and 13C4 are shown in SEQ ID NOs: 1-12. The amino acid sequences of the V_(H) CDR2s of 1D4, 1E1, 2G1, 3C4, 6A5, 6A8, 6B10, 7C10, 8F6, 10A12 and 13C4 are shown in SEQ ID NOs: 13-23. The amino acid sequences of the V_(H) CDR3s of 1D4, 1E1, 2G1, 3C4, 6A5, 6A8, 6B10, 7C10, 8F6, 10A12 and 13C4 are shown in SEQ ID NOs: 24-34. The amino acid sequences of the V_(k) CDR1s of 1D4, 1E1, 2G1, 3C4, 6A5, 6A8, 6B10, 7C10, 8F6, 10A12 and 13C4 are shown in SEQ ID NOs: 51-61. The amino acid sequences of the V_(k) CDR2s of 1D4, 1E1, 2G1, 3C4, 6A5, 6A8, 6B10, 7C10, 8F6, 10A12 and 13C4 are shown in SEQ ID NOs: 62-72. The amino acid sequences of the V_(k) CDR1s of 1D4, 1E1, 2G1, 3C4, 6A5, 6A8, 6B10, 7C10, 8F6, 10A12 and 13C4 are shown in SEQ ID NOs: 73-83. The CDR regions are delineated using the Kabat system (Kabat, E. A., et al. (1991) Sequences of Proteins of Immunological Interest, Fifth Edition, U.S. Department of Health and Human Services, NIH Publication No. 91-3242).

Given that each of these antibodies can bind to IP-10 and that antigen-binding specificity is provided primarily by the CDR1, 2 and 3 regions, the V_(H) CDR1, 2 and 3 sequences and V_(L) CDR1, 2 and 3 sequences can be “mixed and matched” (i.e., CDRs from different antibodies can be mixed and match, although each antibody must contain a V_(H) CDR1, 2 and 3 and a V_(L) CDR1, 2 and 3) to create other anti-IP-10 binding molecules of the invention. IP-10 binding of such “mixed and matched” antibodies can be tested using the binding assays described above and in the Examples (e.g., ELISAs). Preferably, when V_(H) CDR sequences are mixed and matched, the CDR1, CDR2 and/or CDR3 sequence from a particular V_(H) sequence is replaced with a structurally similar CDR sequence(s). Likewise, when V_(L) CDR sequences are mixed and matched, the CDR1, CDR2 and/or CDR3 sequence from a particular V_(L) sequence preferably is replaced with a structurally similar CDR sequence(s). For example, the V_(H) CDR1s of 1D4, 1E1, 2G1, 6A5, 6A8, 6B10, 7C10, 8F6, 10A12 and 10A12S share some structural similarity and therefore are amenable to mixing and matching, whereas the V_(H) CDR1s of 3C4 and 13C4 are not structurally similar to the V_(H) CDR1s of 1D4, 1E1, 2G1, 6A5, 6A8, 6B10, 7C10, 8F6, 10A12 and 10A12S and thus should not be mixed and matched with them. It will be readily apparent to the ordinarily skilled artisan that novel V_(H) and V_(L) sequences can be created by substituting one or more V_(H) and/or V_(L) CDR region sequences with structurally similar sequences from the CDR sequences disclosed herein for monoclonal antibodies antibodies 1D4, 1E1, 2G1, 3C4, 6A5, 6A8, 6B10, 7C10, 8F6, 10A12 and 13C4.

Accordingly, in another aspect, the invention provides an isolated monoclonal antibody, or antigen binding portion thereof comprising:

(a) a heavy chain variable region CDR1 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 1-12;

(b) a heavy chain variable region CDR2 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 13-23;

(c) a heavy chain variable region CDR3 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 24-34;

(d) a light chain variable region CDR1 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 51-61;

(e) a light chain variable region CDR2 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 62-72; and

(f) a light chain variable region CDR3 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 73-83;

wherein the antibody specifically binds IP-10.

In a preferred embodiment, the antibody comprises:

(a) a heavy chain variable region CDR1 comprising SEQ ID NO: 1;

(b) a heavy chain variable region CDR2 comprising SEQ ID NO: 13;

(c) a heavy chain variable region CDR3 comprising SEQ ID NO: 24;

(d) a light chain variable region CDR1 comprising SEQ ID NO: 51;

(e) a light chain variable region CDR2 comprising SEQ ID NO: 62; and

(f) a light chain variable region CDR3 comprising SEQ ID NO: 73.

In another preferred embodiment, the antibody comprises:

(a) a heavy chain variable region CDR1 comprising SEQ ID NO: 2;

(b) a heavy chain variable region CDR2 comprising SEQ ID NO: 14;

(c) a heavy chain variable region CDR3 comprising SEQ ID NO: 25;

(d) a light chain variable region CDR1 comprising SEQ ID NO: 52;

(e) a light chain variable region CDR2 comprising SEQ ID NO: 63; and

(f) a light chain variable region CDR3 comprising SEQ ID NO: 74.

In another preferred embodiment, the antibody comprises:

(a) a heavy chain variable region CDR1 comprising SEQ ID NO: 3;

(b) a heavy chain variable region CDR2 comprising SEQ ID NO: 15;

(c) a heavy chain variable region CDR3 comprising SEQ ID NO: 26;

(d) a light chain variable region CDR1 comprising SEQ ID NO: 53;

(e) a light chain variable region CDR2 comprising SEQ ID NO: 64; and

(f) a light chain variable region CDR3 comprising SEQ ID NO: 75.

In another preferred embodiment, the antibody comprises:

(a) a heavy chain variable region CDR1 comprising SEQ ID NO: 4;

(b) a heavy chain variable region CDR2 comprising SEQ ID NO: 16;

(c) a heavy chain variable region CDR3 comprising SEQ ID NO: 27;

(d) a light chain variable region CDR1 comprising SEQ ID NO: 54;

(e) a light chain variable region CDR2 comprising SEQ ID NO: 65; and

(f) a light chain variable region CDR3 comprising SEQ ID NO: 76.

In another preferred embodiment, the antibody comprises:

(a) a heavy chain variable region CDR1 comprising SEQ ID NO: 5;

(b) a heavy chain variable region CDR2 comprising SEQ ID NO: 17;

(c) a heavy chain variable region CDR3 comprising SEQ ID NO: 28;

(d) a light chain variable region CDR1 comprising SEQ ID NO: 55;

(e) a light chain variable region CDR2 comprising SEQ ID NO: 66; and

(f) a light chain variable region CDR3 comprising SEQ ID NO: 77.

In another preferred embodiment, the antibody comprises:

(a) a heavy chain variable region CDR1 comprising SEQ ID NO: 6;

(b) a heavy chain variable region CDR2 comprising SEQ ID NO: 18;

(c) a heavy chain variable region CDR3 comprising SEQ ID NO: 29;

(d) a light chain variable region CDR1 comprising SEQ ID NO: 56;

(e) a light chain variable region CDR2 comprising SEQ ID NO: 67; and

(f) a light chain variable region CDR3 comprising SEQ ID NO: 78.

In another preferred embodiment, the antibody comprises:

(a) a heavy chain variable region CDR1 comprising SEQ ID NO: 7;

(b) a heavy chain variable region CDR2 comprising SEQ ID NO: 19;

(c) a heavy chain variable region CDR3 comprising SEQ ID NO: 30;

(d) a light chain variable region CDR1 comprising SEQ ID NO: 57;

(e) a light chain variable region CDR2 comprising SEQ ID NO: 68; and

(f) a light chain variable region CDR3 comprising SEQ ID NO: 79.

In another preferred embodiment, the antibody comprises:

(a) a heavy chain variable region CDR1 comprising SEQ ID NO: 8;

(b) a heavy chain variable region CDR2 comprising SEQ ID NO: 20;

(c) a heavy chain variable region CDR3 comprising SEQ ID NO: 31;

(d) a light chain variable region CDR1 comprising SEQ ID NO: 58;

(e) a light chain variable region CDR2 comprising SEQ ID NO: 69; and

(f) a light chain variable region CDR3 comprising SEQ ID NO: 80.

In another preferred embodiment, the antibody comprises:

(a) a heavy chain variable region CDR1 comprising SEQ ID NO: 9;

(b) a heavy chain variable region CDR2 comprising SEQ ID NO: 21;

(c) a heavy chain variable region CDR3 comprising SEQ ID NO: 32;

(d) a light chain variable region CDR1 comprising SEQ ID NO: 59;

(e) a light chain variable region CDR2 comprising SEQ ID NO: 70; and

(f) a light chain variable region CDR3 comprising SEQ ID NO: 81.

In another preferred embodiment, the antibody comprises:

(a) a heavy chain variable region CDR1 comprising SEQ ID NO: 10 or 11;

(b) a heavy chain variable region CDR2 comprising SEQ ID NO: 22;

(c) a heavy chain variable region CDR3 comprising SEQ ID NO: 33;

(d) a light chain variable region CDR1 comprising SEQ ID NO: 60;

(e) a light chain variable region CDR2 comprising SEQ ID NO: 71; and

(f) a light chain variable region CDR3 comprising SEQ ID NO: 82.

In another preferred embodiment, the antibody comprises:

(a) a heavy chain variable region CDR1 comprising SEQ ID NO: 12;

(b) a heavy chain variable region CDR2 comprising SEQ ID NO: 23;

(c) a heavy chain variable region CDR3 comprising SEQ ID NO: 34;

(d) a light chain variable region CDR1 comprising SEQ ID NO: 61;

(e) a light chain variable region CDR2 comprising SEQ ID NO: 72; and

(f) a light chain variable region CDR3 comprising SEQ ID NO: 83.

Antibodies Having Particular Germline Sequences

In certain embodiments, an antibody of the invention comprises a heavy chain variable region from a particular germline heavy chain immunoglobulin gene and/or a light chain variable region from a particular germline light chain immunoglobulin gene.

As demonstrated herein, human antibodies specific for IP-10 have been prepared that comprise a heavy chain variable region that is the product of or derived from a human germline VH 3-33 gene, VH 3-30.3 gene, VH 5-51 gene or VH 4-61 gene. Accordingly, the invention provides an isolated monoclonal antibody, or an antigen-binding portion thereof, wherein the antibody comprises a heavy chain variable region that is the product of or derived from a human VH germline gene selected from the group consisting of: VH 3-33, VH 3-30.3, VH 5-51 and VH 4-61. Preferably the antibody is specific for a human IP-10 polypeptide (e.g., comprising the sequence of Genbank Acc. No. NP_001556).

Also as demonstrated herein, human antibodies specific for IP-10 have been prepared that comprise a light chain variable region that is the product of or derived from a human germline Vk A27 gene, Vk L15 gene, Vk L6 gene or Vk L18 gene. Accordingly, the invention provides an isolated monoclonal antibody, or an antigen-binding portion thereof, wherein the antibody comprises a light chain variable region that is the product of or derived from a human Vk germline gene selected from the group consisting of: Vk A27, Vk L15, Vk L6 and Vk L18. Preferably the antibody is specific for a human IP-10 polypeptide (e.g., comprising the sequence of Genbank Acc. No. NP_001556).

Preferred antibodies of the invention are those comprising a heavy chain variable region that is the product of or derived from one of the above-listed human germline VH genes and also comprising a light chain variable region that is the product of or derived from one of the above-listed human germline Vk genes. Accordingly, in antoher embodiment, the invention provides an isolated monoclonal antibody, or an antigen-binding portion thereof, wherein the antibody comprises:

(a) a heavy chain variable region that is the product of or derived from a human VH germline gene selected from the group consisting of: VH 3-33, VH 3-30.3, VH 5-51 and VH 4-61; and

(b) a light chain variable region that is the product of or derived from a human Vk germline gene selected from the group consisting of: Vk A27, Vk L15, Vk L6 and Vk L18. Preferably the antibody is specific for a human IP-10 polypeptide (e.g., comprising the sequence of Genbank Acc. No. NP_001556).

The invention also provides antibodies comprising preferred combinations of heavy and light chain variable regions that are the product of or derived from particular VH and Vk germline genes. For example, in a preferred embodiment, the invention provides an isolated monoclonal antibody, or an antigen-binding portion thereof, wherein the antibody:

(a) comprises a heavy chain variable region that is the product of or derived from a human VH 3-33 gene (which encodes the amino acid sequence set forth in SEQ ID NO: 47;

(b) comprises a light chain variable region that is the product of or derived from a human Vk A27, L15 or L6 gene (which encode the amino acid sequences set forth in SEQ ID NOs: 95, 98 and 97, respectively); and

(c) specifically binds to IP-10.

In one embodiment, the antibody comprises a light chain variable region that is the product of or derived from a human Vk A27 gene. Examples of antibodies having V_(H) and V_(K) of VH 3-33 and Vk A27, respectively, include 1D4, 2G1, 6A5, 6A8, 10A12 and 10A12S. In another embodiment, the antibody comprises a light chain variable region that is the product of or derived from a human Vk L15 gene. An example of an antibody having V_(H) and V_(K) of VH 3-33 and Vk L15, respectively, is 7C10. In another embodiment, the antibody comprises a light chain variable region of a human Vk L6 gene. An example of an antibody having V_(H) and V_(K) of VH 3-33 and Vk L6, respectively, is 1E1.

In another preferred embodiment, the invention provides an isolated monoclonal antibody, or an antigen-binding portion thereof, wherein the antibody:

-   -   (a) comprises a heavy chain variable region of or derived from a         human VH 3-30.3 gene (which encodes the amino acid sequence set         forth in SEQ ID NO: 48);     -   (b) comprises a light chain variable region of or derived from a         human Vk L6 gene (which encodies the amino acid sequence set         forth in SEQ ID NO: 96); and     -   (c) specifically binds to IP-10.         Examples of antibodies having V_(H) and V_(K) of VH 3-30.3 and         Vk L6, respectively, include 6B10 and 8F6.

In another preferred embodiment, the invention provides an isolated monoclonal antibody, or an antigen-binding portion thereof, wherein the antibody:

-   -   (a) comprises a heavy chain variable region of or derived from a         human VH 5-51 gene (which encodes the amino acid sequence set         forth in SEQ ID NO:49);     -   (b) comprises a light chain variable region of or derived from a         human Vk L18 gene (which encodes the amino acid sequence set         forth in SEQ ID NO: 97); and     -   (c) specifically binds to IP-10.         An example of an antibody having V_(H) and V_(K) of VH 5-51 and         Vk L18, respectively, is 3C4.

In yet another preferred embodiment, the invention provides an isolated monoclonal antibody, or an antigen-binding portion thereof, wherein the antibody:

-   -   (a) comprises a heavy chain variable region of or derived from a         human VH 4-61 gene (which which encodes the amino acid sequence         set forth in SEQ ID NO:50);     -   (b) comprises a light chain variable region of or derived from a         human Vk A27 gene (which encodes the amino acid sequence set         forth in SEQ ID NO: 95); and     -   (c) specifically binds to IP-10.         An example of an antibody having V_(H) and V_(K) of VH 4-61 and         Vk A27, respectively, is 13C4.

As used herein, a human antibody comprises heavy or light chain variable regions that is “the product of” or “derived from” a particular germline sequence if the variable regions of the antibody are obtained from a system that uses human germline immunoglobulin genes. Such systems include immunizing a transgenic mouse carrying human immunoglobulin genes with the antigen of interest or screening a human immunoglobulin gene library displayed on phage with the antigen of interest. A human antibody that is “the product of” or “derived from” a human germline immunoglobulin sequence can be identified as such by comparing the amino acid sequence of the human antibody to the amino acid sequences of human germline immunoglobulins and selecting the human germline immunoglobulin sequence that is closest in sequence (i.e., greatest % identity) to the sequence of the human antibody. A human antibody that is “the product of” or “derived from” a particular human germline immunoglobulin sequence may contain amino acid differences as compared to the germline sequence, due to, for example, naturally-occurring somatic mutations or intentional introduction of site-directed mutation. However, a selected human antibody typically is at least 90% identical in amino acids sequence to an amino acid sequence encoded by a human germline immunoglobulin gene and contains amino acid residues that identify the human antibody as being human when compared to the germline immunoglobulin amino acid sequences of other species (e.g., murine germline sequences). In certain cases, a human antibody may be at least 95%, or even at least 96%, 97%, 98%, or 99% identical in amino acid sequence to the amino acid sequence encoded by the germline immunoglobulin gene. Typically, a human antibody derived from a particular human germline sequence will display no more than 10 amino acid differences from the amino acid sequence encoded by the human germline immunoglobulin gene. In certain cases, the human antibody may display no more than 5, or even no more than 4, 3, 2, or 1 amino acid difference from the amino acid sequence encoded by the germline immunoglobulin gene.

Homologous Antibodies

In yet another embodiment, an antibody of the invention comprises heavy and light chain variable regions comprising amino acid sequences that are homologous to the amino acid sequences of the preferred antibodies described herein, and wherein the antibodies retain the desired functional properties of the anti-IP-10 antibodies of the invention.

For example, the invention provides an isolated monoclonal antibody, or antigen binding portion thereof, comprising a heavy chain variable region and a light chain variable region, wherein:

-   -   (a) the heavy chain variable region comprises an amino acid         sequence that is at least 80% homologous to an amino acid         sequence selected from the group consisting of SEQ ID NOs:         35-46;     -   (b) the light chain variable region comprises an amino acid         sequence that is at least 80% homologous to an amino acid         sequence selected from the group consisting of SEQ ID NOs:84-94;     -   (c) the antibody specifically binds to IP-10, and     -   (d) the antibody exhibits at least one of the following         functional properties:         -   (i) the antibody inhibits binding of IP-10 to CXCR3;         -   (ii) the antibody inhibits IP-10 induced calcium flux;         -   (iii) the antibody inhibits IP-10 induced cell migration;         -   (iv) the antibody cross-reacts with rhesus monkey IP-10;         -   (v) the antibody does not cross-react with mouse IP-10;         -   (vi) the antibody does not cross-react with human MIG;         -   (vii) the antibody does not cross-react with human ITAC.             In various embodiments, the antibody may exhibit one or             more, two or more, three or more, four or more, five or more             or six or more of the functional properties listed as (d)             through (j) above. The antibody can be, for example, a human             antibody, a humanized antibody or a chimeric antibody.

In other embodiments, the V_(H) and/or V_(L) amino acid sequences may be 85%, 90%, 95%, 96%, 97%, 98% or 99% homologous to the sequences set forth above. An antibody having V_(H) and V_(L) regions having high (i.e., 80% or greater) homology to the V_(H) and V_(L) regions of SEQ ID NOs: 35-46 and 84-94, respectively, can be obtained by mutagenesis (e.g., site-directed or PCR-mediated mutagenesis) of nucleic acid molecules encoding SEQ ID NOs: 35-46 and/or 84-94, followed by testing of the encoded altered antibody for retained function (i.e., the functions set forth in (c) through (j) above) using the functional assays described herein.

As used herein, the percent homology between two amino acid sequences is equivalent to the percent identity between the two sequences. The percent identity between the two sequences is a function of the number of identical positions shared by the sequences (i.e., % homology=# of identical positions/total # of positions×100), taking into account the number of gaps, and the length of each gap, which need to be introduced for optimal alignment of the two sequences. The comparison of sequences and determination of percent identity between two sequences can be accomplished using a mathematical algorithm, as described in the non-limiting examples below.

The percent identity between two amino acid sequences can be determined using the algorithm of E. Meyers and W. Miller (Comput. Appl. Biosci., 4:11-17 (1988)) which has been incorporated into the ALIGN program (version 2.0), using a PAM120 weight residue table, a gap length penalty of 12 and a gap penalty of 4. In addition, the percent identity between two amino acid sequences can be determined using the Needleman and Wunsch (J. Mol. Biol. 48:444-453 (1970)) algorithm which has been incorporated into the GAP program in the GCG software package (available at http://www.gcg.com), using either a Blossum 62 matrix or a PAM250 matrix, and a gap weight of 16, 14, 12, 10, 8, 6, or 4 and a length weight of 1, 2, 3, 4, 5, or 6.

Additionally or alternatively, the protein sequences of the present invention can further be used as a “query sequence” to perform a search against public databases to, for example, identify related sequences. Such searches can be performed using the XBLAST program (version 2.0) of Altschul, et al. (1990) J. Mol. Biol. 215:403-10. BLAST protein searches can be performed with the XBLAST program, score=50, wordlength=3 to obtain amino acid sequences homologous to the antibody molecules of the invention. To obtain gapped alignments for comparison purposes, Gapped BLAST can be utilized as described in Altschul et al., (1997) Nucleic Acids Res. 25(17):3389-3402. When utilizing BLAST and Gapped BLAST programs, the default parameters of the respective programs (e.g., XBLAST and NBLAST) can be used. See http://www.ncbi.nlm.nih.gov.

Antibodies with Conservative Modifications

In certain embodiments, an antibody of the invention comprises a heavy chain variable region comprising CDR1, CDR2 and CDR3 sequences and a light chain variable region comprising CDR1, CDR2 and CDR3 sequences, wherein one or more of these CDR sequences comprise specified amino acid sequences based on the preferred antibodies described herein (e.g., 1D4, 1E1, 2G1, 3C4, 6A5, 6A8, 6B10, 7C10, 8F6, 10A12, 10A12S or 13C4), or conservative modifications thereof, and wherein the antibodies retain the desired functional properties of the anti-IP-10 antibodies of the invention. Accordingly, the invention provides an isolated monoclonal antibody, or antigen binding portion thereof, comprising a heavy chain variable region comprising CDR1, CDR2, and CDR3 sequences and a light chain variable region comprising CDR1, CDR2, and CDR3 sequences, wherein:

-   -   (a) the heavy chain variable region CDR3 sequence comprises an         amino acid sequence selected from the group consisting of amino         acid sequences of SEQ ID NOs: 24-34, and conservative         modifications thereof;     -   (b) the light chain variable region CDR3 sequence comprises an         amino acid sequence selected from the group consisting of amino         acid sequence of SEQ ID NOs: 73-83, and conservative         modifications thereof;     -   (c) the antibody specifically binds to IP-10, and     -   (d) the antibody exhibits at least one of the following         functional properties:         -   (i) the antibody inhibits binding of IP-10 to CXCR3;         -   (ii) the antibody inhibits IP-10 induced calcium flux;         -   (iii) the antibody inhibits IP-10 induced cell migration;         -   (iv) the antibody cross-reacts with rhesus monkey IP-10;         -   (v) the antibody does not cross-react with mouse IP-10;         -   (vi) the antibody does not cross-react with human MIG;         -   (vii) the antibody does not cross-react with human ITAC.             In a preferred embodiment, the heavy chain variable region             CDR2 sequence comprises an amino acid sequence selected from             the group consisting of amino acid sequences of SEQ ID NOs:             13-23, and conservative modifications thereof; and the light             chain variable region CDR2 sequence comprises an amino acid             sequence selected from the group consisting of amino acid             sequences of SEQ ID NOs: 62-72, and conservative             modifications thereof. In another preferred embodiment, the             heavy chain variable region CDR3 sequence comprises an amino             acid sequence selected from the group consisting of amino             acid sequences of SEQ ID NOs: 1-12, and conservative             modifications thereof; and the light chain variable region             CDR3 sequence comprises an amino acid sequence selected from             the group consisting of amino acid sequences of SEQ ID NOs:             51-61, and conservative modifications thereof.

In various embodiments, the antibody may exhibit one or more, two or more, three or more, four or more, five or more or six or more of the functional properties listed as (d) through (j) above. Such antibodies can be, for example, human antibodies, humanized antibodies or chimeric antibodies.

As used herein, the term “conservative sequence modifications” is intended to refer to amino acid modifications that do not significantly affect or alter the binding characteristics of the antibody containing the amino acid sequence. Such conservative modifications include amino acid substitutions, additions and deletions. Modifications can be introduced into an antibody of the invention by standard techniques known in the art, such as site-directed mutagenesis and PCR-mediated mutagenesis. Conservative amino acid substitutions are ones in which the amino acid residue is replaced with an amino acid residue having a similar side chain. Families of amino acid residues having similar side chains have been defined in the art. These families include amino acids with basic side chains (e.g., lysine, arginine, histidine), acidic side chains (e.g., aspartic acid, glutamic acid), uncharged polar side chains (e.g., glycine, asparagine, glutamine, serine, threonine, tyrosine, cysteine, tryptophan), nonpolar side chains (e.g., alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine), beta-branched side chains (e.g., threonine, valine, isoleucine) and aromatic side chains (e.g., tyrosine, phenylalanine, tryptophan, histidine). Thus, one or more amino acid residues within the CDR regions of an antibody of the invention can be replaced with other amino acid residues from the same side chain family and the altered antibody can be tested for retained function (i.e., the functions set forth in (c) through (j) above) using the functional assays described herein.

Antibodies that Bind to the Same Epitope as Anti-IP-10 Antibodies of the Invention

In another embodiment, the invention provides antibodies that bind to the same epitope as do the various anti-IP-10 antibodies of the invention provided herein, such as other human antibodies that bind to the same epitope as the 1D4, 1E1, 2G1, 3C4, 6A5, 6A8, 6B10, 7C10, 8F6, 10A12, 10A12S or 13C4 antibodies described herein. Such additional antibodies can be identified based on their ability to cross-compete (e.g., to competitively inhibit the binding of, in a statistically significant manner) with other antibodies of the invention, such as 1D4, 1E1, 2G1, 3C4, 6A5, 6A8, 6B10, 7C10, 8F6, 10A12, 10A12S or 13C4, in standard IP-10 binding assays. The ability of a test antibody to inhibit the binding of, e.g., 1D4, 1E1, 2G1, 3C4, 6A5, 6A8, 6B10, 7C10, 8F6, 10A12, 10A12S or 13C4 to human IP-10 demonstrates that the test antibody can compete with that antibody for binding to human IP-10; such an antibody may, according to non-limiting theory, bind to the same or a related (e.g., a structurally similar or spatially proximal) epitope on human IP-10 as the antibody with which it competes. In a preferred embodiment, the antibody that binds to the same epitope on human IP-10 as 1D4, 1E1, 2G1, 3C4, 6A5, 6A8, 6B10, 7C10, 8F6, 10A12, 10A12S or 13C4 is a human monoclonal antibody. Such human monoclonal antibodies can be prepared and isolated as described in the Examples.

Engineered and Modified Antibodies

An antibody of the invention further can be prepared using an antibody having one or more of the V_(H) and/or V_(L) sequences disclosed herein as starting material to engineer a modified antibody, which modified antibody may have altered properties from the starting antibody. An antibody can be engineered by modifying one or more residues within one or both variable regions (i.e., V_(H) and/or V_(L)), for example within one or more CDR regions and/or within one or more framework regions. Additionally or alternatively, an antibody can be engineered by modifying residues within the constant region(s), for example to alter the effector function(s) of the antibody.

One type of variable region engineering that can be performed is CDR grafting. Antibodies interact with target antigens predominantly through amino acid residues that are located in the six heavy and light chain complementarity determining regions (CDRs). For this reason, the amino acid sequences within CDRs are more diverse between individual antibodies than sequences outside of CDRs. Because CDR sequences are responsible for most antibody-antigen interactions, it is possible to express recombinant antibodies that mimic the properties of specific naturally occurring antibodies by constructing expression vectors that include CDR sequences from the specific naturally occurring antibody grafted onto framework sequences from a different antibody with different properties (see, e.g., Riechmann, L. et al. (1998) Nature 332:323-327; Jones, P. et al. (1986) Nature 321:522-525; Queen, C. et al. (1989) Proc. Natl. Acad. See. U.S.A. 86:10029-10033; U.S. Pat. No. 5,225,539 to Winter, and U.S. Pat. Nos. 5,530,101; 5,585,089; 5,693,762 and 6,180,370 to Queen et al.)

Accordingly, another embodiment of the invention pertains to an isolated monoclonal antibody, or antigen binding portion thereof, comprising a heavy chain variable region comprising CDR1, CDR2, and CDR3 sequences comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 1-12, SEQ ID NOs: 13-23 and SEQ ID NOs: 24-34, respectively, and a light chain variable region comprising CDR1, CDR2, and CDR3 sequences comprising an amino acid sequence selected from the group consisting of SEQ ID NOs:51-61, SEQ ID NOs: 62-72 and SEQ ID NOs: 73-83, respectively. Thus, such antibodies contain the V_(H) and V_(L) CDR sequences of monoclonal antibodies 1D4, 1E1, 2G1, 3C4, 6A5, 6A8, 6B10, 7C10, 8F6, 10A12, 10A125 or 13C4 yet may contain different framework sequences from these antibodies.

Such framework sequences can be obtained from public DNA databases or published references that include germline antibody gene sequences. For example, germline DNA sequences for human heavy and light chain variable region genes can be found in the “VBase” human germline sequence database (available on the Internet at www.mrc-cpe.cam.ac.uk/vbase), as well as in Kabat, E. A., et al. (1991) Sequences of Proteins of Immunological Interest, Fifth Edition, U.S. Department of Health and Human Services, NIH Publication No. 91-3242; Tomlinson, I. M., et al. (1992) “The Repertoire of Human Germline V_(H) Sequences Reveals about Fifty Groups of V_(H) Segments with Different Hypervariable Loops” J. Mol. Biol. 227:776-798; and Cox, J. P. L. et al. (1994) “A Directory of Human Germ-line V_(H) Segments Reveals a Strong Bias in their Usage” Eur. J. Immunol. 24:827-836; the contents of each of which are expressly incorporated herein by reference.

Preferred framework sequences for use in the antibodies of the invention are those that are structurally similar to the framework sequences used by selected antibodies of the invention, e.g., similar to the V_(H) 3-33, 3-30.3, 4-61 or 5-51 sequences [SEQ ID NOS:47-50] and/or V_(k) A27, L6, L18 or L15 framework sequences [SEQ ID NOS:95-98] used by preferred monoclonal antibodies of the invention. The V_(H) CDR1, 2 and 3 sequences, and the V_(L) CDR1, 2 and 3 sequences, can be grafted onto framework regions that have the identical sequence as that found in the germline immunoglobulin gene from which the framework sequence derive, or the CDR sequences can be grafted onto framework regions that contain one or more mutations as compared to the germline sequences. For example, it has been found that in certain instances it is beneficial to mutate residues within the framework regions to maintain or enhance the antigen binding ability of the antibody (see e.g., U.S. Pat. Nos. 5,530,101; 5,585,089; 5,693,762 and 6,180,370 to Queen et al).

Another type of variable region modification is to mutate amino acid residues within the V_(H) and/or V_(L) CDR1, CDR2 and/or CDR3 regions to thereby improve one or more binding properties (e.g., affinity) of the antibody of interest. Site-directed mutagenesis or PCR-mediated mutagenesis can be performed to introduce the mutation(s) and the effect on antibody binding, or other functional property of interest, can be evaluated in in vitro or in vivo assays as described herein and provided in the Examples. Preferably conservative modifications (as discussed above) are introduced. The mutations may be amino acid substitutions, additions or deletions, but are preferably substitutions. Moreover, typically no more than one, two, three, four or five residues within a CDR region are altered.

Accordingly, in another embodiment, the invention provides isolated anti-IP-10 monoclonal antibodies, or antigen binding portions thereof, comprising a heavy chain variable region comprising: (a) a V_(H) CDR1 region comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 1-12, or an amino acid sequence having one, two, three, four or five amino acid substitutions, deletions or additions as compared to SEQ ID NOs: 1-12; (b) a V_(H) CDR2 region comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 13-23, or an amino acid sequence having one, two, three, four or five amino acid substitutions, deletions or additions as compared to SEQ ID NOs: 13-23; (c) a V_(H) CDR3 region comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 24-34, or an amino acid sequence having one, two, three, four or five amino acid substitutions, deletions or additions as compared to SEQ ID NOs: 24-34; (d) a V_(L) CDR1 region comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 51-61, or an amino acid sequence having one, two, three, four or five amino acid substitutions, deletions or additions as compared to SEQ ID NOs: 51-61; (e) a V_(L) CDR2 region comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 62-72, or an amino acid sequence having one, two, three, four or five amino acid substitutions, deletions or additions as compared to SEQ ID NOs: 62-72; and (f) a V_(L) CDR3 region comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 73-83, or an amino acid sequence having one, two, three, four or five amino acid substitutions, deletions or additions as compared to SEQ ID NOs: 73-83.

A preferred substitution mutation of the invention is the substitution of a serine residue for the cysteine residue at position 32, within CDR1, of the V_(H) chain of the 10A12 mAb. This modified form of 10A12 is referred to herein as 10A12S. The amino acid sequence of the V_(H) chain of 10A12 is shown in SEQ ID NO: 44 and the amino acid sequence of the V_(H) chain of 10A12S is shown in SEQ ID NO: 45.

Engineered antibodies of the invention include those in which modifications have been made to framework residues within V_(H) and/or V_(L), e.g. to improve the properties of the antibody. Typically such framework modifications are made to decrease the immunogenicity of the antibody. For example, one approach is to “backmutate” one or more framework residues to the corresponding germline sequence. More specifically, an antibody that has undergone somatic mutation may contain framework residues that differ from the germline sequence from which the antibody is derived. Such residues can be identified by comparing the antibody framework sequences to the germline sequences from which the antibody is derived. For example, for 6A5, amino acid residue #2 (within FR1) of V_(H) is a methionine whereas this residue in the corresponding V_(H) 3-33 germline sequence is a valine (see FIG. 12). To return the framework region sequences to their germline configuration, the somatic mutations can be “backmutated” to the germline sequence by, for example, site-directed mutagenesis or PCR-mediated mutagenesis (e.g., residue 2 of the V_(H) of 6A5 can be “backmutated” from methionine to valine). Such “backmutated” antibodies are also intended to be encompassed by the invention.

Another type of framework modification involves mutating one or more residues within the framework region, or even within one or more CDR regions, to remove T cell epitopes to thereby reduce the potential immunogenicity of the antibody. This approach is also referred to as “deimmunization” and is described in further detail in U.S. Patent Publication No. 20030153043 by Carr et al.

In addition or alternative to modifications made within the framework or CDR regions, antibodies of the invention may be engineered to include modifications within the Fc region, typically to alter one or more functional properties of the antibody, such as serum half-life, complement fixation, Fc receptor binding, and/or antigen-dependent cellular cytotoxicity. Furthermore, an antibody of the invention may be chemically modified (e.g., one or more chemical moieties can be attached to the antibody) or be modified to alter its glycosylation, again to alter one or more functional properties of the antibody. Each of these embodiments is described in further detail below. The numbering of residues in the Fc region is that of the EU index of Kabat.

In one embodiment, the hinge region of CH1 is modified such that the number of cysteine residues in the hinge region is altered, e.g., increased or decreased. This approach is described further in U.S. Pat. No. 5,677,425 by Bodmer et al. The number of cysteine residues in the hinge region of CH1 is altered to, for example, facilitate assembly of the light and heavy chains or to increase or decrease the stability of the antibody.

In another embodiment, the Fc hinge region of an antibody is mutated to decrease the biological half life of the antibody. More specifically, one or more amino acid mutations are introduced into the CH2-CH3 domain interface region of the Fc-hinge fragment such that the antibody has impaired Staphylococcyl protein A (SpA) binding relative to native Fc-hinge domain SpA binding. This approach is described in further detail in U.S. Pat. No. 6,165,745 by Ward et al.

In another embodiment, the antibody is modified to increase its biological half life. Various approaches are possible. For example, one or more of the following mutations can be introduced: T252L, T254S, T256F, as described in U.S. Pat. No. 6,277,375 to Ward. Alternatively, to increase the biological half life, the antibody can be altered within the CH1 or CL region to contain a salvage receptor binding epitope taken from two loops of a CH2 domain of an Fc region of an IgG, as described in U.S. Pat. Nos. 5,869,046 and 6,121,022 by Presta et al.

In yet other embodiments, the Fc region is altered by replacing at least one amino acid residue with a different amino acid residue to alter the effector function(s) of the antibody. For example, one or more amino acids selected from amino acid residues 234, 235, 236, 237, 297, 318, 320 and 322 can be replaced with a different amino acid residue such that the antibody has an altered affinity for an effector ligand but retains the antigen-binding ability of the parent antibody. The effector ligand to which affinity is altered can be, for example, an Fc receptor or the C1 component of complement. This approach is described in further detail in U.S. Pat. Nos. 5,624,821 and 5,648,260, both by Winter et al.

In another example, one or more amino acids selected from amino acid residues 329, 331 and 322 can be replaced with a different amino acid residue such that the antibody has altered C1q binding and/or reduced or abolished complement dependent cytotoxicity (CDC). This approach is described in further detail in U.S. Pat. No. 6,194,551 by Idusogie et al.

In another example, one or more amino acid residues within amino acid positions 231 and 239 are altered to thereby alter the ability of the antibody to fix complement. This approach is described further in PCT Publication WO 94/29351 by Bodmer et al.

In yet another example, the Fc region is modified to increase the ability of the antibody to mediate antibody dependent cellular cytotoxicity (ADCC) and/or to increase the affinity of the antibody for an Fcγ receptor by modifying one or more amino acids at the following positions: 238, 239, 248, 249, 252, 254, 255, 256, 258, 265, 267, 268, 269, 270, 272, 276, 278, 280, 283, 285, 286, 289, 290, 292, 293, 294, 295, 296, 298, 301, 303, 305, 307, 309, 312, 315, 320, 322, 324, 326, 327, 329, 330, 331, 333, 334, 335, 337, 338, 340, 360, 373, 376, 378, 382, 388, 389, 398, 414, 416, 419, 430, 434, 435, 437, 438 or 439. This approach is described further in PCT Publication WO 00/42072 by Presta. Moreover, the binding sites on human IgG1 for FcγR1, FcγRII, FcγRIII and FcRn have been mapped and variants with improved binding have been described (see Shields, R. L. et al. (2001) J. Biol. Chem. 276:6591-6604). Specific mutations at positions 256, 290, 298, 333, 334 and 339 were shown to improve binding to FcγRIII. Additionally, the following combination mutants were shown to improve FcγRIII binding: T256A/S298A, S298A/E333A, S298A/K₂₂₄A and S298A/E333A/K₃₃₄A.

In still another embodiment, the glycosylation of an antibody is modified. For example, an aglycoslated antibody can be made (i.e., the antibody lacks glycosylation). Glycosylation can be altered to, for example, increase the affinity of the antibody for antigen. Such carbohydrate modifications can be accomplished by, for example, altering one or more sites of glycosylation within the antibody sequence. For example, one or more amino acid substitutions can be made that result in elimination of one or more variable region framework glycosylation sites to thereby eliminate glycosylation at that site. Such aglycosylation may increase the affinity of the antibody for antigen. Such an approach is described in further detail in U.S. Pat. Nos. 5,714,350 and 6,350,861 by Co et al.

Additionally or alternatively, an antibody can be made that has an altered type of glycosylation, such as a hypofucosylated antibody having reduced amounts of fucosyl residues or an antibody having increased bisecting GlcNac structures. Such altered glycosylation patterns have been demonstrated to increase the ADCC ability of antibodies. Such carbohydrate modifications can be accomplished by, for example, expressing the antibody in a host cell with altered glycosylation machinery. Cells with altered glycosylation machinery have been described in the art and can be used as host cells in which to express recombinant antibodies of the invention to thereby produce an antibody with altered glycosylation. For example, EP 1,176,195 by Hanai et al. describes a cell line with a functionally disrupted FUT8 gene, which encodes a fucosyl transferase, such that antibodies expressed in such a cell line exhibit hypofucosylation. PCT Publication WO 03/035835 by Presta describes a variant CHO cell line, Lec13 cells, with reduced ability to attach fucose to Asn(297)-linked carbohydrates, also resulting in hypofucosylation of antibodies expressed in that host cell (see also Shields, R. L. et al. (2002) J. Biol. Chem. 277:26733-26740). PCT Publication WO 99/54342 by Umana et al. describes cell lines engineered to express glycoprotein-modifying glycosyl transferases (e.g., beta(1,4)-N-acetylglucosaminyltransferase III (GnTIII)) such that antibodies expressed in the engineered cell lines exhibit increased bisecting GlcNac structures which results in increased ADCC activity of the antibodies (see also Umana et al. (1999) Nat. Biotech. 17:176-180).

Another modification of the antibodies herein that is contemplated by the invention is pegylation. An antibody can be pegylated to, for example, increase the biological (e.g., serum) half life of the antibody. To pegylate an antibody, the antibody, or fragment thereof, typically is reacted with polyethylene glycol (PEG), such as a reactive ester or aldehyde derivative of PEG, under conditions in which one or more PEG groups become attached to the antibody or antibody fragment. Preferably, the pegylation is carried out via an acylation reaction or an alkylation reaction with a reactive PEG molecule (or an analogous reactive water-soluble polymer). As used herein, the term “polyethylene glycol” is intended to encompass any of the forms of PEG that have been used to derivatize other proteins, such as mono (C1-C10) alkoxy- or aryloxy-polyethylene glycol or polyethylene glycol-maleimide. In certain embodiments, the antibody to be pegylated is an aglycosylated antibody. Methods for pegylating proteins are known in the art and can be applied to the antibodies of the invention. See for example, EP 0 154 316 by Nishimura et al. and EP 0 401 384 by Ishikawa et al.

Methods of Engineering Antibodies

As discussed above, the anti-IP-10 antibodies having V_(H) and V_(L) sequences disclosed herein can be used to create new anti-IP-10 antibodies by modifying the VH and/or VL sequences, or the constant region(s) attached thereto. Thus, in another aspect of the invention, the structural features of an anti-IP-10 antibody of the invention, e.g. 1D4, 1E1, 2G1, 3C4, 6A5, 6A8, 6B10, 7C10, 8F6, 10A12, 10A12S or 13C4, are used to create structurally related anti-IP-10 antibodies that retain at least one functional property of the antibodies of the invention, such as binding to human IP-10 and rhesus monkey IP-10, but not to mouse IP-10 or human MIG or human ITAC, and also inhibiting one or more functional properties of IP-10 (e.g., CXCR3 binding, calcium flux, chemotaxis). For example, one or more CDR regions of 1D4, 1E1, 2G1, 3C4, 6A5, 6A8, 6B10, 7C10, 8F6, 10A12, 10A12S or 13C4, or mutations thereof, can be combined recombinantly with known framework regions and/or other CDRs to create additional, recombinantly-engineered, anti-IP-10 antibodies of the invention, as discussed above. Other types of modifications include those described in the previous section. The starting material for the engineering method is one or more of the V_(H) and/or V_(L) sequences provided herein, or one or more CDR regions thereof. To create the engineered antibody, it is not necessary to actually prepare (i.e., express as a protein) an antibody having one or more of the V_(H) and/or V_(L) sequences provided herein, or one or more CDR regions thereof. Rather, the information contained in the sequence(s) is used as the starting material to create a “second generation” sequence(s) derived from the original sequence(s) and then the “second generation” sequence(s) is prepared and expressed as a protein.

Accordingly, in another embodiment, the invention provides a method for preparing an anti-IP-10 antibody comprising:

-   -   (a) providing: (i) a heavy chain variable region antibody         sequence comprising a CDR1 sequence selected from the group         consisting of SEQ ID NOs: 1-12, a CDR2 sequence selected from         the group consisting of SEQ ID NOs: 13-23 and/or a CDR3 sequence         selected from the group consisting of SEQ ID NOs: 24-34;         and (ii) a light chain variable region antibody sequence         comprising a CDR1 sequence selected from the group consisting of         SEQ ID NOs: 51-61, a CDR2 sequence selected from the group         consisting of SEQ ID NOs: 62-72 and/or a CDR3 sequence selected         from the group consisting of SEQ ID NOs: 73-83;     -   (b) altering at least one amino acid residue within the heavy         chain variable region antibody sequence and/or the light chain         variable region antibody sequence to create at least one altered         antibody sequence; and     -   (c) expressing the altered antibody sequence as a protein.

Standard molecular biology techniques can be used to prepare and express the altered antibody sequence.

Preferably, the antibody encoded by the altered antibody sequence(s) is one that retains one, some or all of the functional properties of the anti-IP-10 antibodies described herein, which functional properties include, but are not limited to:

-   -   (i) specifically binds to human IP-10;     -   (ii) inhibits binding of IP-10 to CXCR3;     -   (iii) inhibits IP-10 induced calcium flux;     -   (iv) inhibits IP-10 induced cell migration;     -   (v) cross-reacts with rhesus monkey IP-10;     -   (vi) does not cross-react with mouse IP-10;     -   (vii) does not cross-react with human MIG; and     -   (viii) does not cross-react with human ITAC.         The altered antibody may exhibit one or more, two or more, three         or more, four or more, five or more, six or more or seven or         more of the functional properties set forth as (i)         through (viii) above.

The functional properties of the altered antibodies can be assessed using standard assays available in the art and/or described herein, such as those set forth in the Examples (e.g., ELISAs, calcium flux assays, chemotaxis assays).

In certain embodiments of the methods of engineering antibodies of the invention, mutations can be introduced randomly or selectively along all or part of an anti-IP-10 antibody coding sequence and the resulting modified anti-IP-10 antibodies can be screened for binding activity and/or other functional properties as described herein. Mutational methods have been described in the art. For example, PCT Publication WO 02/092780 by Short describes methods for creating and screening antibody mutations using saturation mutagenesis, synthetic ligation assembly, or a combination thereof. Alternatively, PCT Publication WO 03/074679 by Lazar et al. describes methods of using computational screening methods to optimize physiochemical properties of antibodies.

Nucleic Acid Molecules Encoding Antibodies of the Invention

Another aspect of the invention pertains to nucleic acid molecules that encode the antibodies of the invention. The nucleic acids may be present in whole cells, in a cell lysate, or in a partially purified or substantially pure form. A nucleic acid is “isolated” or “rendered substantially pure” when purified away from other cellular components or other contaminants, e.g., other cellular nucleic acids or proteins, by standard techniques, including alkaline/SDS treatment, CsCl banding, column chromatography, agarose gel electrophoresis and others well known in the art. See, F. Ausubel, et al., ed. (1987) Current Protocols in Molecular Biology, Greene Publishing and Wiley Interscience, New York. A nucleic acid of the invention can be, for example, DNA or RNA and may or may not contain intronic sequences. In a preferred embodiment, the nucleic acid is a cDNA molecule.

Nucleic acids of the invention can be obtained using standard molecular biology techniques. For antibodies expressed by hybridomas (e.g., hybridomas prepared from transgenic mice carrying human immunoglobulin genes as described further below), cDNAs encoding the light and heavy chains of the antibody made by the hybridoma can be obtained by standard PCR amplification or cDNA cloning techniques. For antibodies obtained from an immunoglobulin gene library (e.g., using phage display techniques), nucleic acid encoding the antibody can be recovered from the library.

Preferred nucleic acids molecules of the invention are those encoding the VH and VL sequences of the 1D4, 1E1, 2G1, 3C4, 6A5, 6A8, 6B10, 7C10, 8F6, 10A12 or 13C4 monoclonal antibodies. DNA sequences encoding the VH sequences of 1D4, 1E1, 2G1, 3C4, 6A5, 6A8, 6B10, 7C10, 8F6, 10A12 and 13C4 are shown in SEQ ID NOs: 99-109, respectively. DNA sequences encoding the VL sequences of 1D4, 1E1, 2G1, 3C4, 6A5, 6A8, 6B10, 7C10, 8F6, 10A12 and 13C4 are shown in SEQ ID NOs: 110-120, respectively.

Once DNA fragments encoding VH and VL segments are obtained, these DNA fragments can be further manipulated by standard recombinant DNA techniques, for example to convert the variable region genes to full-length antibody chain genes, to Fab fragment genes or to a scFv gene. In these manipulations, a VL- or VH-encoding DNA fragment is operatively linked to another DNA fragment encoding another protein, such as an antibody constant region or a flexible linker. The term “operatively linked”, as used in this context, is intended to mean that the two DNA fragments are joined such that the amino acid sequences encoded by the two DNA fragments remain in-frame.

The isolated DNA encoding the VH region can be converted to a full-length heavy chain gene by operatively linking the VH-encoding DNA to another DNA molecule encoding heavy chain constant regions (CH1, CH2 and CH3). The sequences of human heavy chain constant region genes are known in the art (see e.g., Kabat, E. A., et al. (1991) Sequences of Proteins of Immunological Interest, Fifth Edition, U.S. Department of Health and Human Services, NIH Publication No. 91-3242) and DNA fragments encompassing these regions can be obtained by standard PCR amplification. The heavy chain constant region can be an IgG1, IgG2, IgG3, IgG4, IgA, IgE, IgM or IgD constant region, but most preferably is an IgG1 or IgG4 constant region. For a Fab fragment heavy chain gene, the VH-encoding DNA can be operatively linked to another DNA molecule encoding only the heavy chain CH1 constant region.

The isolated DNA encoding the VL region can be converted to a full-length light chain gene (as well as a Fab light chain gene) by operatively linking the VL-encoding DNA to another DNA molecule encoding the light chain constant region, CL. The sequences of human light chain constant region genes are known in the art (see e.g., Kabat, E. A., et al. (1991) Sequences of Proteins of Immunological Interest, Fifth Edition, U.S. Department of Health and Human Services, NIH Publication No. 91-3242) and DNA fragments encompassing these regions can be obtained by standard PCR amplification. The light chain constant region can be a kappa or lambda constant region, but most preferably is a kappa constant region.

To create a scFv gene, the VH- and VL-encoding DNA fragments are operatively linked to another fragment encoding a flexible linker, e.g., encoding the amino acid sequence (Gly₄-Ser)₃, such that the VH and VL sequences can be expressed as a contiguous single-chain protein, with the VL and VH regions joined by the flexible linker (see e.g., Bird et al. (1988) Science 242:423-426; Huston et al. (1988) Proc. Natl. Acad. Sci. USA 85:5879-5883; McCafferty et al., (1990) Nature 348:552-554).

Production of Monoclonal Antibodies of the Invention

Monoclonal antibodies (mAbs) of the present invention can be produced by a variety of techniques, including conventional monoclonal antibody methodology e.g., the standard somatic cell hybridization technique of Kohler and Milstein (1975) Nature 256: 495. Although somatic cell hybridization procedures are preferred, in principle, other techniques for producing monoclonal antibody can be employed e.g., viral or oncogenic transformation of B lymphocytes.

The preferred animal system for preparing hybridomas is the murine system. Hybridoma production in the mouse is a very well-established procedure. Immunization protocols and techniques for isolation of immunized splenocytes for fusion are known in the art. Fusion partners (e.g., murine myeloma cells) and fusion procedures are also known.

Chimeric or humanized antibodies of the present invention can be prepared based on the sequence of a murine monoclonal antibody prepared as described above. DNA encoding the heavy and light chain immunoglobulins can be obtained from the murine hybridoma of interest and engineered to contain non-murine (e.g., human) immunoglobulin sequences using standard molecular biology techniques. For example, to create a chimeric antibody, the murine variable regions can be linked to human constant regions using methods known in the art (see e.g., U.S. Pat. No. 4,816,567 to Cabilly et al.). To create a humanized antibody, the murine CDR regions can be inserted into a human framework using methods known in the art (see e.g., U.S. Pat. No. 5,225,539 to Winter, and U.S. Pat. Nos. 5,530,101; 5,585,089; 5,693,762 and 6,180,370 to Queen et al.).

In a preferred embodiment, the antibodies of the invention are human monoclonal antibodies. Such human monoclonal antibodies directed against IP-10 can be generated using transgenic or transchromosomic mice carrying parts of the human immune system rather than the mouse system. These transgenic and transchromosomic mice include mice referred to herein as HuMAb mice and KM mice, respectively, and are collectively referred to herein as “human Ig mice.”

The HuMAb Mouse® (Medarex, Inc.) contains human immunoglobulin gene miniloci that encode unrearranged human heavy (μ and γ) and κ light chain immunoglobulin sequences, together with targeted mutations that inactivate the endogenous μ and κ chain loci (see e.g., Lonberg, et al. (1994) Nature 368(6474): 856-859). Accordingly, the mice exhibit reduced expression of mouse IgM or κ, and in response to immunization, the introduced human heavy and light chain transgenes undergo class switching and somatic mutation to generate high affinity human IgGκ monoclonal (Lonberg, N. et al. (1994), supra; reviewed in Lonberg, N. (1994) Handbook of Experimental Pharmacology 113:49-101; Lonberg, N. and Huszar, D. (1995) Intern. Rev. Immunol. 13: 65-93, and Harding, F. and Lonberg, N. (1995) Ann. N.Y. Acad. Sci. 764:536-546). The preparation and use of HuMab mice, and the genomic modifications carried by such mice, is further described in Taylor, L. et al. (1992) Nucleic Acids Research 20:6287-6295; Chen, J. et al. (1993) International Immunology 5: 647-656; Tuaillon et al. (1993) Proc. Natl. Acad. Sci. USA 90:3720-3724; Choi et al. (1993) Nature Genetics 4:117-123; Chen, J. et al. (1993) EMBO J. 12: 821-830; Tuaillon et al. (1994) J. Immunol. 152:2912-2920; Taylor, L. et al. (1994) International Immunology 6: 579-591; and Fishwild, D. et al. (1996) Nature Biotechnology 14: 845-851, the contents of all of which are hereby specifically incorporated by reference in their entirety. See further, U.S. Pat. Nos. 5,545,806; 5,569,825; 5,625,126; 5,633,425; 5,789,650; 5,877,397; 5,661,016; 5,814,318; 5,874,299; and 5,770,429; all to Lonberg and Kay; U.S. Pat. No. 5,545,807 to Surani et al.; PCT Publication Nos. WO 92/03918, WO 93/12227, WO 94/25585, WO 97/13852, WO 98/24884 and WO 99/45962, all to Lonberg and Kay; and PCT Publication No. WO 01/14424 to Korman et al.

In another embodiment, human antibodies of the invention can be raised using a mouse that carries human immunoglobulin sequences on transgenes and transchomosomes, such as a mouse that carries a human heavy chain transgene and a human light chain transchromosome. Such mice, referred to herein as “KM mice”, are described in detail in PCT Publication WO 02/43478 to Ishida et al.

Still further, alternative transgenic animal systems expressing human immunoglobulin genes are available in the art and can be used to raise anti-IP-10 antibodies of the invention. For example, an alternative transgenic system referred to as the Xenomouse (Abgenix, Inc.) can be used; such mice are described in, for example, U.S. Pat. Nos. 5,939,598; 6,075,181; 6,114,598; 6, 150,584 and 6,162,963 to Kucherlapati et al.

Moreover, alternative transchromosomic animal systems expressing human immunoglobulin genes are available in the art and can be used to raise anti-IP-10 antibodies of the invention. For example, mice carrying both a human heavy chain transchromosome and a human light chain tranchromosome, referred to as “TC mice” can be used; such mice are described in Tomizuka et al. (2000) Proc. Natl. Acad. Sci. USA 97:722-727. Furthermore, cows carrying human heavy and light chain transchromosomes have been described in the art (Kuroiwa et al. (2002) Nature Biotechnology 20:889-894) and can be used to raise anti-IP-10 antibodies of the invention.

Human monoclonal antibodies of the invention can also be prepared using phage display methods for screening libraries of human immunoglobulin genes. Such phage display methods for isolating human antibodies are established in the art. See for example: U.S. Pat. Nos. 5,223,409; 5,403,484; and U.S. Pat. No. 5,571,698 to Ladner et al.; U.S. Pat. Nos. 5,427,908 and 5,580,717 to Dower et al.; U.S. Pat. Nos. 5,969,108 and 6,172,197 to McCafferty et al.; and U.S. Pat. Nos. 5,885,793; 6,521,404; 6,544,731; 6,555,313; 6,582,915 and 6,593,081 to Griffiths et al.

Human monoclonal antibodies of the invention can also be prepared using SCID mice into which human immune cells have been reconstituted such that a human antibody response can be generated upon immunization. Such mice are described in, for example, U.S. Pat. Nos. 5,476,996 and 5,698,767 to Wilson et al.

Immunization of Human Ig Mice

When human Ig mice are used to raise human antibodies of the invention, such mice can be immunized with a purified or enriched preparation of IP-10 antigen and/or recombinant IP-10, or an IP-10 fusion protein, as described by Lonberg, N. et al. (1994) Nature 368(6474): 856-859; Fishwild, D. et al. (1996) Nature Biotechnology 14: 845-851; and PCT Publication WO 98/24884 and WO 01/14424. Preferably, the mice will be 6-16 weeks of age upon the first infusion. For example, a purified or recombinant preparation (5-50 μg) of IP-10 antigen can be used to immunize the human Ig mice intraperitoneally.

Detailed procedures to generate fully human monoclonal antibodies to IP-10 are described in Example 1 below. Cumulative experience with various antigens has shown that the transgenic mice respond when initially immunized intraperitoneally (IP) with antigen in complete Freund's adjuvant, followed by every other week IP immunizations (up to a total of 6) with antigen in incomplete Freund's adjuvant. However, adjuvants other than Freund's are also found to be effective. In addition, whole cells in the absence of adjuvant are found to be highly immunogenic. The immune response can be monitored over the course of the immunization protocol with plasma samples being obtained by retroorbital bleeds. The plasma can be screened by ELISA (as described below), and mice with sufficient titers of anti-IP-10 human immunoglobulin can be used for fusions. Mice can be boosted intravenously with antigen 3 days before sacrifice and removal of the spleen. It is expected that 2-3 fusions for each immunization may need to be performed. Between 6 and 24 mice are typically immunized for each antigen. Usually both HCo7 and HCo12 strains are used. In addition, both HCo7 and HCo12 transgene can be bred together into a single mouse having two different human heavy chain transgenes (HCo7/HCo12).

Generation of Hybridomas Producing Human Monoclonal Antibodies of the Invention

To generate hybridomas producing human monoclonal antibodies of the invention, splenocytes and/or lymph node cells from immunized mice can be isolated and fused to an appropriate immortalized cell line, such as a mouse myeloma cell line. The resulting hybridomas can be screened for the production of antigen-specific antibodies. For example, single cell suspensions of splenic lymphocytes from immunized mice can be fused to one-sixth the number of P3×63-Ag8.653 nonsecreting mouse myeloma cells (ATCC, CRL 1580) with 50% PEG. Cells are plated at approximately 2×10⁵ in flat bottom microtiter plate, followed by a two week incubation in selective medium containing 20% fetal Clone Serum, 18% “653” conditioned media, 5% origen (IGEN), 4 mM L-glutamine, 1 mM sodium pyruvate, 5 mM HEPES, 0.055 mM 2-mercaptoethanol, 50 units/ml penicillin, 50 mg/ml streptomycin, 50 mg/ml gentamycin and 1×HAT (Sigma; the HAT is added 24 hours after the fusion). After approximately two weeks, cells can be cultured in medium in which the HAT is replaced with HT. Individual wells can then be screened by ELISA for human monoclonal IgM and IgG antibodies. Once extensive hybridoma growth occurs, medium can be observed usually after 10-14 days. The antibody secreting hybridomas can be replated, screened again, and if still positive for human IgG, the monoclonal antibodies can be subcloned at least twice by limiting dilution. The stable subclones can then be cultured in vitro to generate small amounts of antibody in tissue culture medium for characterization.

To purify human monoclonal antibodies, selected hybridomas can be grown in two-liter spinner-flasks for monoclonal antibody purification. Supernatants can be filtered and concentrated before affinity chromatography with protein A-sepharose (Pharmacia, Piscataway, N.J.). Eluted IgG can be checked by gel electrophoresis and high performance liquid chromatography to ensure purity. The buffer solution can be exchanged into PBS, and the concentration can be determined by OD280 using 1.43 extinction coefficient. The monoclonal antibodies can be aliquoted and stored at −80° C.

Generation of Transfectomas Producing Monoclonal Antibodies of the Invention

Antibodies of the invention also can be produced in a host cell transfectoma using, for example, a combination of recombinant DNA techniques and gene transfection methods as is well known in the art (e.g., Morrison, S. (1985) Science 229:1202).

For example, to express the antibodies, or antibody fragments thereof, DNAs encoding partial or full-length light and heavy chains, can be obtained by standard molecular biology techniques (e.g., PCR amplification or cDNA cloning using a hybridoma that expresses the antibody of interest) and the DNAs can be inserted into expression vectors such that the genes are operatively linked to transcriptional and translational control sequences. In this context, the term “operatively linked” is intended to mean that an antibody gene is ligated into a vector such that transcriptional and translational control sequences within the vector serve their intended function of regulating the transcription and translation of the antibody gene. The expression vector and expression control sequences are chosen to be compatible with the expression host cell used. The antibody light chain gene and the antibody heavy chain gene can be inserted into separate vector or, more typically, both genes are inserted into the same expression vector. The antibody genes are inserted into the expression vector by standard methods (e.g., ligation of complementary restriction sites on the antibody gene fragment and vector, or blunt end ligation if no restriction sites are present). The light and heavy chain variable regions of the antibodies described herein can be used to create full-length antibody genes of any antibody isotype by inserting them into expression vectors already encoding heavy chain constant and light chain constant regions of the desired isotype such that the V_(H) segment is operatively linked to the C_(H) segment(s) within the vector and the V_(L) segment is operatively linked to the C_(L) segment within the vector. Additionally or alternatively, the recombinant expression vector can encode a signal peptide that facilitates secretion of the antibody chain from a host cell. The antibody chain gene can be cloned into the vector such that the signal peptide is linked in-frame to the amino terminus of the antibody chain gene. The signal peptide can be an immunoglobulin signal peptide or a heterologous signal peptide (i.e., a signal peptide from a non-immunoglobulin protein).

In addition to the antibody chain genes, the recombinant expression vectors of the invention carry regulatory sequences that control the expression of the antibody chain genes in a host cell. The term “regulatory sequence” is intended to include promoters, enhancers and other expression control elements (e.g., polyadenylation signals) that control the transcription or translation of the antibody chain genes. Such regulatory sequences are described, for example, in Goeddel (Gene Expression Technology. Methods in Enzymology 185, Academic Press, San Diego, Calif. (1990)). It will be appreciated by those skilled in the art that the design of the expression vector, including the selection of regulatory sequences, may depend on such factors as the choice of the host cell to be transformed, the level of expression of protein desired, etc. Preferred regulatory sequences for mammalian host cell expression include viral elements that direct high levels of protein expression in mammalian cells, such as promoters and/or enhancers derived from cytomegalovirus (CMV), Simian Virus 40 (SV40), adenovirus, (e.g., the adenovirus major late promoter (AdMLP) and polyoma. Alternatively, nonviral regulatory sequences may be used, such as the ubiquitin promoter or β-globin promoter. Still further, regulatory elements composed of sequences from different sources, such as the SRα promoter system, which contains sequences from the SV40 early promoter and the long terminal repeat of human T cell leukemia virus type 1 (Takebe, Y. et al. (1988) Mol. Cell. Biol. 8:466-472).

In addition to the antibody chain genes and regulatory sequences, the recombinant expression vectors of the invention may carry additional sequences, such as sequences that regulate replication of the vector in host cells (e.g., origins of replication) and selectable marker genes. The selectable marker gene facilitates selection of host cells into which the vector has been introduced (see, e.g., U.S. Pat. Nos. 4,399,216, 4,634,665 and 5,179,017, all by Axel et al.). For example, typically the selectable marker gene confers resistance to drugs, such as G418, hygromycin or methotrexate, on a host cell into which the vector has been introduced. Preferred selectable marker genes include the dihydrofolate reductase (DHFR) gene (for use in dhfr-host cells with methotrexate selection/amplification) and the neo gene (for G418 selection).

For expression of the light and heavy chains, the expression vector(s) encoding the heavy and light chains is transfected into a host cell by standard techniques. The various forms of the term “transfection” are intended to encompass a wide variety of techniques commonly used for the introduction of exogenous DNA into a prokaryotic or eukaryotic host cell, e.g., electroporation, calcium-phosphate precipitation, DEAE-dextran transfection and the like. Although it is theoretically possible to express the antibodies of the invention in either prokaryotic or eukaryotic host cells, expression of antibodies in eukaryotic cells, and most preferably mammalian host cells, is the most preferred because such eukaryotic cells, and in particular mammalian cells, are more likely than prokaryotic cells to assemble and secrete a properly folded and immunologically active antibody. Prokaryotic expression of antibody genes has been reported to be ineffective for production of high yields of active antibody (Boss, M. A. and Wood, C. R. (1985) Immunology Today 6:12-13).

Preferred mammalian host cells for expressing the recombinant antibodies of the invention include Chinese Hamster Ovary (CHO cells) (including dhfr-CHO cells, described in Urlaub and Chasin, (1980) Proc. Natl. Acad. Sci. USA 77:4216-4220, used with a DHFR selectable marker, e.g., as described in R. J. Kaufman and P. A. Sharp (1982) Mol. Biol. 159:601-621), NSO myeloma cells, COS cells and SP2 cells. In particular, for use with NSO myeloma cells, another preferred expression system is the GS gene expression system disclosed in WO 87/04462, WO 89/01036 and EP 338,841. When recombinant expression vectors encoding antibody genes are introduced into mammalian host cells, the antibodies are produced by culturing the host cells for a period of time sufficient to allow for expression of the antibody in the host cells or, more preferably, secretion of the antibody into the culture medium in which the host cells are grown. Antibodies can be recovered from the culture medium using standard protein purification methods.

Characterization of Antibody Binding to Antigen

Antibodies of the invention can be tested for binding to IP-10 by, for example, standard ELISA. Briefly, microtiter plates are coated with purified IP-10 at 0.25 μg/ml in PBS, and then blocked with 5% bovine serum albumin in PBS. Dilutions of antibody (e.g., dilutions of plasma from IP-10-immunized mice) are added to each well and incubated for 1-2 hours at 37° C. The plates are washed with PBS/Tween and then incubated with secondary reagent (e.g., for human antibodies, a goat-anti-human IgG Fc-specific polyclonal reagent) conjugated to alkaline phosphatase for 1 hour at 37° C. After washing, the plates are developed with pNPP substrate (1 mg/ml), and analyzed at OD of 405-650. Preferably, mice which develop the highest titers will be used for fusions.

An ELISA assay as described above can also be used to screen for hybridomas that show positive reactivity with IP-10 immunogen. Hybridomas that bind with high avidity to IP-10 are subcloned and further characterized. One clone from each hybridoma, which retains the reactivity of the parent cells (by ELISA), can be chosen for making a 5-10 vial cell bank stored at −140° C., and for antibody purification.

To purify anti-IP-10 antibodies, selected hybridomas can be grown in two-liter spinner-flasks for monoclonal antibody purification. Supernatants can be filtered and concentrated before affinity chromatography with protein A-sepharose (Pharmacia, Piscataway, N.J.). Eluted IgG can be checked by gel electrophoresis and high performance liquid chromatography to ensure purity. The buffer solution can be exchanged into PBS, and the concentration can be determined by OD₂₈₀ using 1.43 extinction coefficient. The monoclonal antibodies can be aliquoted and stored at −80° C.

To determine if the selected anti-IP-10 monoclonal antibodies bind to unique epitopes, each antibody can be biotinylated using commercially available reagents (Pierce, Rockford, Ill.). Competition studies using unlabeled monoclonal antibodies and biotinylated monoclonal antibodies can be performed using IP-10 coated-ELISA plates as described above. Biotinylated mAb binding can be detected with a strep-avidin-alkaline phosphatase probe.

To determine the isotype of purified antibodies, isotype ELISAs can be performed using reagents specific for antibodies of a particular isotype. For example, to determine the isotype of a human monoclonal antibody, wells of microtiter plates can be coated with 1 μg/ml of anti-human immunoglobulin overnight at 4° C. After blocking with 1% BSA, the plates are reacted with 1 μg/ml or less of test monoclonal antibodies or purified isotype controls, at ambient temperature for one to two hours. The wells can then be reacted with either human IgG1 or human IgM-specific alkaline phosphatase-conjugated probes. Plates are developed and analyzed as described above.

Anti-IP-10 human IgGs can be further tested for reactivity with IP-10 antigen by Western blotting. Briefly, IP-10 can be prepared and subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis. After electrophoresis, the separated antigens are transferred to nitrocellulose membranes, blocked with 10% fetal calf serum, and probed with the monoclonal antibodies to be tested. Human IgG binding can be detected using anti-human IgG alkaline phosphatase and developed with BCIP/NBT substrate tablets (Sigma Chem. Co., St. Louis, Mo.).

Immunoconjugates

In another aspect, the present invention features an anti-IP-10 antibody, or a fragment thereof, conjugated to a therapeutic moiety, such as a cytotoxin, a drug (e.g., an immunosuppressant) or a radiotoxin. Such conjugates are referred to herein as “immunoconjugates” Immunoconjugates that include one or more cytotoxins are referred to as “immunotoxins.” A cytotoxin or cytotoxic agent includes any agent that is detrimental to (e.g., kills) cells. Examples include taxol, cytochalasin B, gramicidin D, ethidium bromide, emetine, mitomycin, etoposide, tenoposide, vincristine, vinblastine, colchicin, doxorubicin, daunorubicin, dihydroxy anthracin dione, mitoxantrone, mithramycin, actinomycin D, 1-dehydrotestosterone, glucocorticoids, procaine, tetracaine, lidocaine, propranolol, and puromycin and analogs or homologs thereof. Therapeutic agents also include, for example, antimetabolites (e.g., methotrexate, 6-mercaptopurine, 6-thioguanine, cytarabine, 5-fluorouracil decarbazine), alkylating agents (e.g., mechlorethamine, thioepa chlorambucil, melphalan, carmustine (BSNU) and lomustine (CCNU), cyclothosphamide, busulfan, dibromomannitol, streptozotocin, mitomycin C, and cis-dichlorodiamine platinum (II) (DDP) cisplatin), anthracyclines (e.g., daunorubicin (formerly daunomycin) and doxorubicin), antibiotics (e.g., dactinomycin (formerly actinomycin), bleomycin, mithramycin, and anthramycin (AMC)), and anti-mitotic agents (e.g., vincristine and vinblastine).

Other preferred examples of therapeutic cytotoxins that can be conjugated to an antibody of the invention include duocarmycins, calicheamicins, maytansines and auristatins, and derivatives thereof. An example of a calicheamicin antibody conjugate is commercially available (Mylotarg™; Wyeth-Ayerst).

Cytoxins can be conjugated to antibodies of the invention using linker technology available in the art. Examples of linker types that have been used to conjugate a cytotoxin to an antibody include, but are not limited to, hydrazones, thioethers, esters, disulfides and peptide-containing linkers. A linker can be chosen that is, for example, susceptible to cleavage by low pH within the lysosomal compartment or susceptible to cleavage by proteases, such as proteases preferentially expressed in tumor tissue such as cathepsins (e.g., cathepsins B, C, D).

For further discussion of types of cytotoxins, linkers and methods for conjugating therapeutic agents to antibodies, see also Saito, G. et al. (2003) Adv. Drug Deliv. Rev. 55:199-215; Trail, P. A. et al. (2003) Cancer Immunol. Immunother. 52:328-337; Payne, G. (2003) Cancer Cell 3:207-212; Allen, T. M. (2002) Nat. Rev. Cancer 2:750-763; Pastan, I. and Kreitman, R. J. (2002) Curr. Opin. Investig. Drugs 3:1089-1091; Senter, P. D. and Springer, C. J. (2001) Adv. Drug Deliv. Rev. 53:247-264.

Antibodies of the present invention also can be conjugated to a radioactive isotope to generate cytotoxic radiopharmaceuticals, also referred to as radioimmunoconjugates. Examples of radioactive isotopes that can be conjugated to antibodies for use diagnostically or therapeutically include, but are not limited to, iodine¹³¹, indium¹¹¹, yttrium⁹⁰ and lutetium¹⁷⁷. Method for preparing radioimmunconjugates are established in the art. Examples of radioimmunoconjugates are commercially available, including Zevalin™ (IDEC Pharmaceuticals) and Bexxar™ (Corixa Pharmaceuticals), and similar methods can be used to prepare radioimmunoconjugates using the antibodies of the invention.

The antibody conjugates of the invention can be used to modify a given biological response, and the drug moiety is not to be construed as limited to classical chemical therapeutic agents. For example, the drug moiety may be a protein or polypeptide possessing a desired biological activity. Such proteins may include, for example, an enzymatically active toxin, or active fragment thereof, such as abrin, ricin A, pseudomonas exotoxin, or diphtheria toxin; a protein such as tumor necrosis factor or interferon-γ; or, biological response modifiers such as, for example, lymphokines, interleukin-1 (“IL-1”), interleukin-2 (“IL-2”), interleukin-6 (“IL-6”), granulocyte macrophage colony stimulating factor (“GM-CSF”), granulocyte colony stimulating factor (“G-CSF”), or other growth factors.

Techniques for conjugating such therapeutic moiety to antibodies are well known, see, e.g., Amon et al., “Monoclonal Antibodies For Immunotargeting Of Drugs In Cancer Therapy”, in Monoclonal Antibodies And Cancer Therapy, Reisfeld et al. (eds.), pp. 243-56 (Alan R. Liss, Inc. 1985); Hellstrom et al., “Antibodies For Drug Delivery”, in Controlled Drug Delivery (2nd Ed.), Robinson et al. (eds.), pp. 623-53 (Marcel Dekker, Inc. 1987); Thorpe, “Antibody Carriers Of Cytotoxic Agents In Cancer Therapy: A Review”, in Monoclonal Antibodies '84: Biological And Clinical Applications, Pinchera et al. (eds.), pp. 475-506 (1985); “Analysis, Results, And Future Prospective Of The Therapeutic Use Of Radiolabeled Antibody In Cancer Therapy”, in Monoclonal Antibodies For Cancer Detection And Therapy, Baldwin et al. (eds.), pp. 303-16 (Academic Press 1985), and Thorpe et al., “The Preparation And Cytotoxic Properties Of Antibody-Toxin Conjugates”, Immunol. Rev., 62:119-58 (1982).

Bispecific Molecules

In another aspect, the present invention features bispecific molecules comprising an anti-IP-10 antibody, or a fragment thereof, of the invention. An antibody of the invention, or antigen-binding portions thereof, can be derivatized or linked to another functional molecule, e.g., another peptide or protein (e.g., another antibody or ligand for a receptor) to generate a bispecific molecule that binds to at least two different binding sites or target molecules. The antibody of the invention may in fact be derivatized or linkd to more than one other functional molecule to generate multispecific molecules that bind to more than two different binding sites and/or target molecules; such multispecific molecules are also intended to be encompassed by the term “bispecific molecule” as used herein. To create a bispecific molecule of the invention, an antibody of the invention can be functionally linked (e.g., by chemical coupling, genetic fusion, noncovalent association or otherwise) to one or more other binding molecules, such as another antibody, antibody fragment, peptide or binding mimetic, such that a bispecific molecule results.

Accordingly, the present invention includes bispecific molecules comprising at least one first binding specificity for IP-10 and a second binding specificity for a second target epitope. In a particular embodiment of the invention, the second target epitope is an Fc receptor, e.g., human FcγRI (CD64) or a human Fcα receptor (CD89). Therefore, the invention includes bispecific molecules capable of binding both to FcγR, FcαR or FcϵR expressing effector cells (e.g., monocytes, macrophages or polymorphonuclear cells (PMNs)), and to target cells expressing IP-10. These bispecific molecules target IP-10 expressing cells to effector cell and trigger Fc receptor-mediated effector cell activities, such as phagocytosis of an IP-10 expressing cells, antibody dependent cell-mediated cytotoxicity (ADCC), cytokine release, or generation of superoxide anion.

In an embodiment of the invention in which the bispecific molecule is multispecific, the molecule can further include a third binding specificity, in addition to an anti-Fc binding specificity and an anti-IP-10 binding specificity. In one embodiment, the third binding specificity is an anti-enhancement factor (EF) portion, e.g., a molecule which binds to a surface protein involved in cytotoxic activity and thereby increases the immune response against the target cell. The “anti-enhancement factor portion” can be an antibody, functional antibody fragment or a ligand that binds to a given molecule, e.g., an antigen or a receptor, and thereby results in an enhancement of the effect of the binding determinants for the F_(C) receptor or target cell antigen. The “anti-enhancement factor portion” can bind an F_(C) receptor or a target cell antigen. Alternatively, the anti-enhancement factor portion can bind to an entity that is different from the entity to which the first and second binding specificities bind. For example, the anti-enhancement factor portion can bind a cytotoxic T-cell (e.g. via CD2, CD3, CD8, CD28, CD4, CD40, ICAM-1 or other immune cell that results in an increased immune response against the target cell).

In one embodiment, the bispecific molecules of the invention comprise as a binding specificity at least one antibody, or an antibody fragment thereof, including, e.g., an Fab, Fab′, F(ab′)₂, Fv, or a single chain Fv. The antibody may also be a light chain or heavy chain dimer, or any minimal fragment thereof such as a Fv or a single chain construct as described in Ladner et al. U.S. Pat. No. 4,946,778, the contents of which is expressly incorporated by reference.

In one embodiment, the binding specificity for an Fcγ receptor is provided by a monoclonal antibody, the binding of which is not blocked by human immunoglobulin G (IgG). As used herein, the term “IgG receptor” refers to any of the eight γ-chain genes located on chromosome 1. These genes encode a total of twelve transmembrane or soluble receptor isoforms which are grouped into three Fcγ receptor classes: FcγRI (CD64), FcγRII(CD32), and FcγRIII (CD16). In one preferred embodiment, the Fcγ receptor a human high affinity FcγRI. The human FcγRI is a 72 kDa molecule, which shows high affinity for monomeric IgG (10⁸-10⁹M⁻¹).

The production and characterization of certain preferred anti-Fcγ monoclonal antibodies are described by Fanger et al. in PCT Publication WO 88/00052 and in U.S. Pat. No. 4,954,617, the teachings of which are fully incorporated by reference herein. These antibodies bind to an epitope of FcγRI, FcγRII or FcγRIII at a site which is distinct from the Fcγ binding site of the receptor and, thus, their binding is not blocked substantially by physiological levels of IgG. Specific anti-FcγRI antibodies useful in this invention are mAb 22, mAb 32, mAb 44, mAb 62 and mAb 197. The hybridoma producing mAb 32 is available from the American Type Culture Collection, ATCC Accession No. HB9469. In other embodiments, the anti-Fcγ receptor antibody is a humanized form of monoclonal antibody 22 (H22). The production and characterization of the H22 antibody is described in Graziano, R. F. et al. (1995) J. Immunol 155 (10): 4996-5002 and PCT Publication WO 94/10332. The H22 antibody producing cell line was deposited at the American Type Culture Collection under the designation HA022CL1 and has the accession no. CRL 11177.

In still other preferred embodiments, the binding specificity for an Fc receptor is provided by an antibody that binds to a human IgA receptor, e.g., an Fc-alpha receptor (FcαRI (CD89)), the binding of which is preferably not blocked by human immunoglobulin A (IgA). The term “IgA receptor” is intended to include the gene product of one α-gene (FcαRI) located on chromosome 19. This gene is known to encode several alternatively spliced transmembrane isoforms of 55 to 110 kDa. Fcα RI (CD89) is constitutively expressed on monocytes/macrophages, eosinophilic and neutrophilic granulocytes, but not on non-effector cell populations. FcαRI has medium affinity (=5×10⁷M⁻¹) for both IgA1 and IgA2, which is increased upon exposure to cytokines such as G-CSF or GM-CSF (Morton, H. C. et al. (1996) Critical Reviews in Immunology 16:423-440). Four FcαRI-specific monoclonal antibodies, identified as A3, A59, A62 and A77, which bind FcαRI outside the IgA ligand binding domain, have been described (Monteiro, R. C. et al. (1992) J. Immunol. 148:1764).

FcαRI and FcγRI are preferred trigger receptors for use in the bispecific molecules of the invention because they are (1) expressed primarily on immune effector cells, e.g., monocytes, PMNs, macrophages and dendritic cells; (2) expressed at high levels (e.g., 5,000-100,000 per cell); (3) mediators of cytotoxic activities (e.g., ADCC, phagocytosis); (4) mediate enhanced antigen presentation of antigens, including self-antigens, targeted to them.

While human monoclonal antibodies are preferred, other antibodies which can be employed in the bispecific molecules of the invention are murine, chimeric and humanized monoclonal antibodies.

The bispecific molecules of the present invention can be prepared by conjugating the constituent binding specificities, e.g., the anti-FcR and anti-IP-10 binding specificities, using methods known in the art. For example, each binding specificity of the bispecific molecule can be generated separately and then conjugated to one another. When the binding specificities are proteins or peptides, a variety of coupling or cross-linking agents can be used for covalent conjugation. Examples of cross-linking agents include protein A, carbodiimide, N-succinimidyl-5-acetyl-thioacetate (SATA), 5,5′-dithiobis(2-nitrobenzoic acid) (DTNB), o-phenylenedimaleimide (oPDM), N-succinimidyl-3-(2-pyridyldithio)propionate (SPDP), and sulfosuccinimidyl 4-(N-maleimidomethyl)cyclohaxane-1-carboxylate (sulfo-SMCC) (see e.g., Karpovsky et al. (1984) J. Exp. Med. 160:1686; Liu, M A et al. (1985) Proc. Natl. Acad. Sci. USA 82:8648). Other methods include those described in Paulus (1985) Behring Ins. Mitt. No. 78, 118-132; Brennan et al. (1985) Science 229:81-83), and Glennie et al. (1987) J. Immunol. 139: 2367-2375). Preferred conjugating agents are SATA and sulfo-SMCC, both available from Pierce Chemical Co. (Rockford, Ill.).

When the binding specificities are antibodies, they can be conjugated via sulfhydryl bonding of the C-terminus hinge regions of the two heavy chains. In a particularly preferred embodiment, the hinge region is modified to contain an odd number of sulfhydryl residues, preferably one, prior to conjugation.

Alternatively, both binding specificities can be encoded in the same vector and expressed and assembled in the same host cell. This method is particularly useful where the bispecific molecule is a mAb×mAb, mAb×Fab, Fab×F(ab′)₂ or ligand x Fab fusion protein. A bispecific molecule of the invention can be a single chain molecule comprising one single chain antibody and a binding determinant, or a single chain bispecific molecule comprising two binding determinants. Bispecific molecules may comprise at least two single chain molecules. Methods for preparing bispecific molecules are described for example in U.S. Pat. No. 5,260,203; U.S. Pat. No. 5,455,030; U.S. Pat. No. 4,881,175; U.S. Pat. No. 5,132,405; U.S. Pat. No. 5,091,513; U.S. Pat. No. 5,476,786; U.S. Pat. No. 5,013,653; U.S. Pat. No. 5,258,498; and U.S. Pat. No. 5,482,858.

Binding of the bispecific molecules to their specific targets can be confirmed by, for example, enzyme-linked immunosorbent assay (ELISA), radioimmunoassay (RIA), FACS analysis, bioassay (e.g., growth inhibition), or Western Blot assay. Each of these assays generally detects the presence of protein-antibody complexes of particular interest by employing a labeled reagent (e.g., an antibody) specific for the complex of interest. For example, the FcR-antibody complexes can be detected using e.g., an enzyme-linked antibody or antibody fragment which recognizes and specifically binds to the antibody-FcR complexes. Alternatively, the complexes can be detected using any of a variety of other immunoassays. For example, the antibody can be radioactively labeled and used in a radioimmunoassay (RIA) (see, for example, Weintraub, B., Principles of Radioimmunoassays, Seventh Training Course on Radioligand Assay Techniques, The Endocrine Society, March, 1986, which is incorporated by reference herein). The radioactive isotope can be detected by such means as the use of a γ counter or a scintillation counter or by autoradiography.

Pharmaceutical Compositions

In another aspect, the present invention provides a composition, e.g., a pharmaceutical composition, containing one or a combination of monoclonal antibodies, or antigen-binding portion(s) thereof, of the present invention, formulated together with a pharmaceutically acceptable carrier. Such compositions may include one or a combination of (e.g., two or more different) antibodies, or immunoconjugates or bispecific molecules of the invention. For example, a pharmaceutical composition of the invention can comprise a combination of antibodies (or immunoconjugates or bispecifics) that bind to different epitopes on the target antigen or that have complementary activities.

Pharmaceutical compositions of the invention also can be administered in combination therapy, i.e., combined with other agents. For example, the combination therapy can include an anti-IP-10 antibody of the present invention combined with at least one other anti-inflammatory or immunosuppressant agent. Examples of therapeutic agents that can be used in combination therapy are described in greater detail below in the section on uses of the antibodies of the invention.

As used herein, “pharmaceutically acceptable carrier” includes any and all solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents, and the like that are physiologically compatible. Preferably, the carrier is suitable for intravenous, intramuscular, subcutaneous, parenteral, spinal or epidermal administration (e.g., by injection or infusion). Depending on the route of administration, the active compound, i.e., antibody, immunoconjuage, or bispecific molecule, may be coated in a material to protect the compound from the action of acids and other natural conditions that may inactivate the compound.

The pharmaceutical compounds of the invention may include one or more pharmaceutically acceptable salts. A “pharmaceutically acceptable salt” refers to a salt that retains the desired biological activity of the parent compound and does not impart any undesired toxicological effects (see e.g., Berge, S. M., et al. (1977) J. Pharm. Sci. 66:1-19). Examples of such salts include acid addition salts and base addition salts. Acid addition salts include those derived from nontoxic inorganic acids, such as hydrochloric, nitric, phosphoric, sulfuric, hydrobromic, hydroiodic, phosphorous and the like, as well as from nontoxic organic acids such as aliphatic mono- and dicarboxylic acids, phenyl-substituted alkanoic acids, hydroxy alkanoic acids, aromatic acids, aliphatic and aromatic sulfonic acids and the like. Base addition salts include those derived from alkaline earth metals, such as sodium, potassium, magnesium, calcium and the like, as well as from nontoxic organic amines, such as N,N′-dibenzylethylenediamine, N-methylglucamine, chloroprocaine, choline, diethanolamine, ethylenediamine, procaine and the like.

A pharmaceutical composition of the invention also may include a pharmaceutically acceptable anti-oxidant. Examples of pharmaceutically acceptable antioxidants include: (1) water soluble antioxidants, such as ascorbic acid, cysteine hydrochloride, sodium bisulfate, sodium metabisulfite, sodium sulfite and the like; (2) oil-soluble antioxidants, such as ascorbyl palmitate, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), lecithin, propyl gallate, alpha-tocopherol, and the like; and (3) metal chelating agents, such as citric acid, ethylenediamine tetraacetic acid (EDTA), sorbitol, tartaric acid, phosphoric acid, and the like.

Examples of suitable aqueous and nonaqueous carriers that may be employed in the pharmaceutical compositions of the invention include water, ethanol, polyols (such as glycerol, propylene glycol, polyethylene glycol, and the like), and suitable mixtures thereof, vegetable oils, such as olive oil, and injectable organic esters, such as ethyl oleate. Proper fluidity can be maintained, for example, by the use of coating materials, such as lecithin, by the maintenance of the required particle size in the case of dispersions, and by the use of surfactants.

These compositions may also contain adjuvants such as preservatives, wetting agents, emulsifying agents and dispersing agents. Prevention of presence of microorganisms may be ensured both by sterilization procedures, supra, and by the inclusion of various antibacterial and antifungal agents, for example, paraben, chlorobutanol, phenol sorbic acid, and the like. It may also be desirable to include isotonic agents, such as sugars, sodium chloride, and the like into the compositions. In addition, prolonged absorption of the injectable pharmaceutical form may be brought about by the inclusion of agents which delay absorption such as aluminum monostearate and gelatin.

Pharmaceutically acceptable carriers include sterile aqueous solutions or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersion. The use of such media and agents for pharmaceutically active substances is known in the art. Except insofar as any conventional media or agent is incompatible with the active compound, use thereof in the pharmaceutical compositions of the invention is contemplated. Supplementary active compounds can also be incorporated into the compositions.

Therapeutic compositions typically must be sterile and stable under the conditions of manufacture and storage. The composition can be formulated as a solution, microemulsion, liposome, or other ordered structure suitable to high drug concentration. The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, polyol (for example, glycerol, propylene glycol, and liquid polyethylene glycol, and the like), and suitable mixtures thereof. The proper fluidity can be maintained, for example, by the use of a coating such as lecithin, by the maintenance of the required particle size in the case of dispersion and by the use of surfactants. In many cases, it will be preferable to include isotonic agents, for example, sugars, polyalcohols such as mannitol, sorbitol, or sodium chloride in the composition. Prolonged absorption of the injectable compositions can be brought about by including in the composition an agent that delays absorption, for example, monostearate salts and gelatin.

Sterile injectable solutions can be prepared by incorporating the active compound in the required amount in an appropriate solvent with one or a combination of ingredients enumerated above, as required, followed by sterilization microfiltration. Generally, dispersions are prepared by incorporating the active compound into a sterile vehicle that contains a basic dispersion medium and the required other ingredients from those enumerated above. In the case of sterile powders for the preparation of sterile injectable solutions, the preferred methods of preparation are vacuum drying and freeze-drying (lyophilization) that yield a powder of the active ingredient plus any additional desired ingredient from a previously sterile-filtered solution thereof.

The amount of active ingredient which can be combined with a carrier material to produce a single dosage form will vary depending upon the subject being treated, and the particular mode of administration. The amount of active ingredient which can be combined with a carrier material to produce a single dosage form will generally be that amount of the composition which produces a therapeutic effect. Generally, out of one hundred percent, this amount will range from about 0.01 percent to about ninety-nine percent of active ingredient, preferably from about 0.1 percent to about 70 percent, most preferably from about 1 percent to about 30 percent of active ingredient in combination with a pharmaceutically acceptable carrier.

Dosage regimens are adjusted to provide the optimum desired response (e.g., a therapeutic response). For example, a single bolus may be administered, several divided doses may be administered over time or the dose may be proportionally reduced or increased as indicated by the exigencies of the therapeutic situation. It is especially advantageous to formulate parenteral compositions in dosage unit form for ease of administration and uniformity of dosage. Dosage unit form as used herein refers to physically discrete units suited as unitary dosages for the subjects to be treated; each unit contains a predetermined quantity of active compound calculated to produce the desired therapeutic effect in association with the required pharmaceutical carrier. The specification for the dosage unit forms of the invention are dictated by and directly dependent on (a) the unique characteristics of the active compound and the particular therapeutic effect to be achieved, and (b) the limitations inherent in the art of compounding such an active compound for the treatment of sensitivity in individuals.

For administration of the antibody, the dosage ranges from about 0.0001 to 100 mg/kg, and more usually 0.01 to 5 mg/kg, of the host body weight. For example dosages can be 0.3 mg/kg body weight, 1 mg/kg body weight, 3 mg/kg body weight, 5 mg/kg body weight or 10 mg/kg body weight or within the range of 1-10 mg/kg. An exemplary treatment regime entails administration once per week, once every two weeks, once every three weeks, once every four weeks, once a month, once every 3 months or once every three to 6 months. Preferred dosage regimens for an anti-IP-10 antibody of the invention include 1 mg/kg body weight or 3 mg/kg body weight via intravenous administration, with the antibody being given using one of the following dosing schedules: (i) every four weeks for six dosages, then every three months; (ii) every three weeks; (iii) 3 mg/kg body weight once followed by 1 mg/kg body weight every three weeks.

In some methods, two or more monoclonal antibodies with different binding specificities are administered simultaneously, in which case the dosage of each antibody administered falls within the ranges indicated. Antibody is usually administered on multiple occasions. Intervals between single dosages can be, for example, weekly, monthly, every three monthgs or yearly. Intervals can also be irregular as indicated by measuring blood levels of antibody to the target antigen in the patient. In some methods, dosage is adjusted to achieve a plasma antibody concentration of about 1-1000 μg/ml and in some methods about 25-300 μg/ml.

Alternatively, antibody can be administered as a sustained release formulation, in which case less frequent administration is required. Dosage and frequency vary depending on the half-life of the antibody in the patient. In general, human antibodies show the longest half life, followed by humanized antibodies, chimeric antibodies, and nonhuman antibodies. The dosage and frequency of administration can vary depending on whether the treatment is prophylactic or therapeutic. In prophylactic applications, a relatively low dosage is administered at relatively infrequent intervals over a long period of time. Some patients continue to receive treatment for the rest of their lives. In therapeutic applications, a relatively high dosage at relatively short intervals is sometimes required until progression of the disease is reduced or terminated, and preferably until the patient shows partial or complete amelioration of symptoms of disease. Thereafter, the patient can be administered a prophylactic regime.

Actual dosage levels of the active ingredients in the pharmaceutical compositions of the present invention may be varied so as to obtain an amount of the active ingredient which is effective to achieve the desired therapeutic response for a particular patient, composition, and mode of administration, without being toxic to the patient. The selected dosage level will depend upon a variety of pharmacokinetic factors including the activity of the particular compositions of the present invention employed, or the ester, salt or amide thereof, the route of administration, the time of administration, the rate of excretion of the particular compound being employed, the duration of the treatment, other drugs, compounds and/or materials used in combination with the particular compositions employed, the age, sex, weight, condition, general health and prior medical history of the patient being treated, and like factors well known in the medical arts.

A “therapeutically effective dosage” of an anti-IP-10 antibody of the invention preferably results in a decrease in severity of disease symptoms, an increase in frequency and duration of disease symptom-free periods, or a prevention of impairment or disability due to the disease affliction. In the case of Rheumatoid Arthritis (RA), a therapeutically effective dose preferably prevents further deterioration of physical symptoms associated with RA, such as, for example, pain, fatigue, morning stiffness (lasting more than one hour), diffuse muscular aches, loss of appetite, weakness, joint pain with warmth, swelling, tenderness, and stiffness of a joint after inactivity. A therapeutically effective dose preferably also prevents or delays onset of RA, such as may be desired when early or preliminary signs of the disease are present. Likewise it includes delaying chronic progression associated with RA. Laboratory tests utilized in the diagnosis of RA include chemistries (including the measurement of IP-10 levels), hematology, serology and radiology. Accordingly, any clinical or biochemical assay that monitors any of the foregoing may be used to determine whether a particular treatment is a therapeutically effective dose for treating RA. One of ordinary skill in the art would be able to determine such amounts based on such factors as the subject's size, the severity of the subject's symptoms, and the particular composition or route of administration selected.

A composition of the present invention can be administered via one or more routes of administration using one or more of a variety of methods known in the art. As will be appreciated by the skilled artisan, the route and/or mode of administration will vary depending upon the desired results. Preferred routes of administration for antibodies of the invention include intravenous, intramuscular, intradermal, intraperitoneal, subcutaneous, spinal or other parenteral routes of administration, for example by injection or infusion. The phrase “parenteral administration” as used herein means modes of administration other than enteral and topical administration, usually by injection, and includes, without limitation, intravenous, intramuscular, intraarterial, intrathecal, intracapsular, intraorbital, intracardiac, intradermal, intraperitoneal, transtracheal, subcutaneous, subcuticular, intraarticular, subcapsular, subarachnoid, intraspinal, epidural and intrasternal injection and infusion.

Alternatively, an antibody of the invention can be administered via a non-parenteral route, such as a topical, epidermal or mucosal route of administration, for example, intranasally, orally, vaginally, rectally, sublingually or topically.

The active compounds can be prepared with carriers that will protect the compound against rapid release, such as a controlled release formulation, including implants, transdermal patches, and microencapsulated delivery systems. Biodegradable, biocompatible polymers can be used, such as ethylene vinyl acetate, polyanhydrides, polyglycolic acid, collagen, polyorthoesters, and polylactic acid. Many methods for the preparation of such formulations are patented or generally known to those skilled in the art. See, e.g., Sustained and Controlled Release Drug Delivery Systems, J. R. Robinson, ed., Marcel Dekker, Inc., New York, 1978.

Therapeutic compositions can be administered with medical devices known in the art. For example, in a preferred embodiment, a therapeutic composition of the invention can be administered with a needleless hypodermic injection device, such as the devices disclosed in U.S. Pat. Nos. 5,399,163; 5,383,851; 5,312,335; 5,064,413; 4,941,880; 4,790,824; or 4,596,556. Examples of well-known implants and modules useful in the present invention include: U.S. Pat. No. 4,487,603, which discloses an implantable micro-infusion pump for dispensing medication at a controlled rate; U.S. Pat. No. 4,486,194, which discloses a therapeutic device for administering medicants through the skin; U.S. Pat. No. 4,447,233, which discloses a medication infusion pump for delivering medication at a precise infusion rate; U.S. Pat. No. 4,447,224, which discloses a variable flow implantable infusion apparatus for continuous drug delivery; U.S. Pat. No. 4,439,196, which discloses an osmotic drug delivery system having multi-chamber compartments; and U.S. Pat. No. 4,475,196, which discloses an osmotic drug delivery system. These patents are incorporated herein by reference. Many other such implants, delivery systems, and modules are known to those skilled in the art.

In certain embodiments, the human monoclonal antibodies of the invention can be formulated to ensure proper distribution in vivo. For example, the blood-brain barrier (BBB) excludes many highly hydrophilic compounds. To ensure that the therapeutic compounds of the invention cross the BBB (if desired), they can be formulated, for example, in liposomes. For methods of manufacturing liposomes, see, e.g., U.S. Pat. Nos. 4,522,811; 5,374,548; and 5,399,331. The liposomes may comprise one or more moieties which are selectively transported into specific cells or organs, thus enhance targeted drug delivery (see, e.g., V. V. Ranade (1989) J. Clin. Pharmacol. 29:685). Exemplary targeting moieties include folate or biotin (see, e.g., U.S. Pat. No. 5,416,016 to Low et al.); mannosides (Umezawa et al., (1988) Biochem. Biophys. Res. Commun. 153:1038); antibodies (P. G. Bloeman et al. (1995) FEBS Lett. 357:140; M. Owais et al. (1995) Antimicrob. Agents Chemother. 39:180); surfactant protein A receptor (Briscoe et al. (1995) Am. J. Physiol. 1233:134); p120 (Schreier et al. (1994) J. Biol. Chem. 269:9090); see also K. Keinanen; M. L. Laukkanen (1994) FEBS Lett. 346:123; J. J. Killion; I. J. Fidler (1994) Immunomethods 4:273.

Uses and Methods of the Invention

The antibodies (and immunoconjugates and bispecific molecules) of the present invention have in vitro and in vivo diagnostic and therapeutic utilities. For example, these molecules can be administered to cells in culture, e.g. in vitro or ex vivo, or in a subject, e.g., in vivo, to treat, prevent or diagnose a variety of disorders. The term “subject” as used herein in intended to includes human and non-human animals. Non-human animals includes all vertebrates, e.g., mammals and non-mammals, such as non-human primates, sheep, dogs, cats, cows, horses, chickens, amphibians, and reptiles. The methods are particularly suitable for treating human patients having a disorder associated with aberrant IP-10 expression. When antibodies to IP-10 are administered together with another agent, the two can be administered in either order or simultaneously.

In one embodiment, the antibodies (and immunoconjugates and bispecific molecules) of the invention can be used to detect levels of IP-10, or levels of cells that contain IP-10. This can be achieved, for example, by contacting a sample (such as an in vitro sample) and a control sample with the anti-IP-10 antibody under conditions that allow for the formation of a complex between the antibody and IP-10. Any complexes formed between the antibody and IP-10 are detected and compared in the sample and the control. For example, standard detection methods, well-known in the art, such as ELISA and flow cytometic assays, can be performed using the compositions of the invention.

Accordingly, in one aspect, the invention further provides methods for detecting the presence of IP-10 (e.g., human IP-10 antigen) in a sample, or measuring the amount of IP-10, comprising contacting the sample, and a control sample, with an antibody of the invention, or an antigen binding portion thereof, which specifically binds to IP-10, under conditions that allow for formation of a complex between the antibody or portion thereof and IP-10. The formation of a complex is then detected, wherein a difference in complex formation between the sample compared to the control sample is indicative of the presence of IP-10 in the sample.

Also within the scope of the invention are kits comprising the compositions (e.g., antibodies, human antibodies, immunoconjugates and bispecific molecules) of the invention and instructions for use. The kit can further contain a least one additional reagent, or one or more additional antibodies of the invention (e.g., an antibody having a complementary activity which binds to an epitope on the target antigen distinct from the first antibody). Kits typically include a label indicating the intended use of the contents of the kit. The term label includes any writing, or recorded material supplied on or with the kit, or which otherwise accompanies the kit.

IP-10 is know to have a chemoattractant effect on activated T cells and NK cells and to recruit such cells to sites of inflammation and autoimmune responses. Accordingly, the anti-IP-10 antibodies (and immunoconjugates and bispecific molecules) of the invention can be used to inhibit inflammatory or autoimmune response mediated by activated T cells and/or NK cells in a variety of clinical indications. The invention, therefore, provides a method of inhibiting an inflammatory or autoimmune response mediated by activated T cells and/or NK cells comprising contacting the T cells or NK cells with an antibody, or antigen-binding portion thereof, of the invention (or immunconjugate or bispecific molecule of the invention) such that the inflammatory or autoimmune response is inhibited. Specific examples of inflammatory or autoimmune conditions in which the antibodies of the invention can be used include, but are not limited to, the following:

a. Multiple Sclerosis and Other Demyelinating Diseases

Expression of IP-10 mRNA has been shown to be increased in murine experimental allergic encephalomyelitis (EAE), a mouse model of multiple sclerosis (Godiska, R. et al. (1995) J. Neuroimmunol. 58:167-176). Moreover, increased levels of IP-10 have been found in the cerebrospinal fluid of MS patients during acute demyelinating events (Sorensen, T. L. et al. (1999) J. Clin. Invest. 103:807-815; Franciotta et al. (2001) J. Neuroimmunol. 115:192-198). IP-10 also has been shown to be expressed by astrocytes in MS lesions, but not in unaffected white matter (Balashov, K. E. et al. (1999) Proc. Natl. Acad. Sci. USA 96:6873-6878) and to be expressed by macrophages within MS plaques and by reactive astrocytes in the surrounding parenchyma (Simpson, J. E. et al. (2000) Neuropathol. Appl. Neurobiol. 26:133-142). PCT Patent Publication WO 02/15932 showed administration of anti-IP-10 antibodies in a mouse hepatitis virus (MHV) model of MS resulted in reduced T lymphocyte and macrophage invasion, inhibited progression of demyelination, increased remyelination and improved neurological function (see also Liu, M. T. et al. (2001) J. Immunol. 167:4091-4097). Administration of murine anti-IP-10 antibodies has been shown to decrease clinical and histological disease incidence and severity in murine EAE (Fife, B. T. et al. (2001) J. Immunol. 166:7617-7624).

In view of the foregoing, the anti-IP-10 antibodies of the invention can be used in the treatment of MS and other demyelinating diseases by administering the antibody to a subject in need of treatment. The antibody can be used alone or in combination with other anti-MS agents, such as interferon beta-1a (e.g., Avonex®, Rebif®), interferon beta-1b (e.g., Betaseron®), glatiramer acetate (e.g., Copaxone®) and/or mitoxantrone (e.g., Novantrone®).

B. Rheumatoid Arthritis

IP-10 levels have been shown to be significantly elevated in synovial fluid, synovial tissue and serum of patients with rheumatoid arthritis (RA) (Patel, D. D. et al. (2001) Clin. Immunol. 98:39-45; Hanaoka, R. et al. (2003) Arthritis Res. and Therapy 5:R74-R81). The IP-10 receptor, CXCR3, has been shown to be preferentially expressed on mast cells within synovial tissue from RA patients (Ruschpler, P. et al. (2003) Arthritis Res. Ther. 5:R241-R252). In an adjuvant induced arthritis (AA) rat model, a detectable autoantibody response against self IP-10 has been reported (Salomon, I. et al. (2002) J. Immunol. 169:2685-2693). Moreover, administration of an IP-10-encoding DNA vaccine augmented production of neutralizing anti-IP-10 antibodies within the rats, and these IP-10 autoantibodies could adoptively transfer resistance to AA to naïve rats (Salomon, I. et al., supra).

In view of the foregoing, the anti-IP-10 antibodies of the invention can be used in the treatment of rheumatoid arthritis by administering the antibody to a subject in need of treatment. The antibody can be used alone or in combination with other anti-RA agents, such as non-steroidal anti-inflammatory drugs (NSAIDs), analgesics, corticosteroids (e.g., prednisone, hydrocortisone), TNF-inhibitors (including adilimumab (Humira®), etanercept (Enbrel®) and infliximab (Remicade®)), disease-modifying anti-rheumatic drugs (including methotrexate, cyclophosphamide, cyclosporine, auranofin, azathioprine, gold sodium thiomalate, hydroxychloroquine sulfate, leflunomide, minocycline, penicillamine and sulfasalazine), fibromyalgia medications, osteoporosis medications and gout medications.

C. Inflammatory Bowel Disease

IP-10 expression has been shown to be significantly enhanced in cells infiltrating the lamina propria of colonic biopsies taken from ulcerative colitis patients (Uguccioni, M. et al. (1999) Am. J. Pathol. 155:331-336). Furthermore, neutralization of IP-10 has been shown to protect mice from epithelial ulceration in acute colitis and to enhance crypt cell survival (Sasaki, S. et al. (2002) Eur. J. Immunol. 32:3197-3205). Also, in IL-10−/− mice, which develop colitis similar to Crohn's disease in humans, treatment with anti-IP-10 antibodies led to improvement in scoring of inflammation (Singh, U. P. et al. (2003) J. Immunol. 171:1401-1406).

In view of the foregoing, the anti-IP-10 antibodies of the invention can be used in the treatment of inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease, by administering the antibody to a subject in need of treatment. The antibody can be used alone or in combination with other anti-IBD agents, such as drugs containing mesalamine (including sulfasalazine and other agents containing 5-aminosalicylic acid (5-ASA), such as olsalazine and balsalazide), non-steroidal anti-inflammatory drugs (NSAIDs), analgesics, corticosteroids (e.g., predinisone, hydrocortisone), TNF-inhibitors (including adilimumab (Humira®), etanercept (Enbrel®) and infliximab (Remicade®)), immunosuppressants (such as 6-mercaptopurine, azathioprine and cyclosporine A), and antibiotics.

D. Systemic Lupus Erythematosus

Serum IP-10 levels have been shown to be markedly increased in patients with systemic lupus erythematosus (SLE) and the levels have been shown to correlate with disease activity (see e.g., Narumi, S. et al. (2000) Cytokine 12:1561-1565). Accordingly, in another embodiment, the anti-IP-10 antibodies of the invention can be used in the treatment of SLE by administering the antibody to a subject in need of treatment. The antibody can be used alone or in combination with other anti-SLE agents, such as non-steroidal anti-inflammatory drugs (NSAIDs), analgesics, corticosteroids (e.g., predinisone, hydrocortisone), immunosuppressants (such as cyclophosphamide, azathioprine, and methotrexate), antimalarials (such as hydroxychloroquine) and biologic drugs that inhibit the production of dsDNA antibodies (e.g., LJP 394).

E. Type I Diabetes

Serum IP-10 levels have been shown to be elevated in patients with Type I diabetes, particularly those with recent onset disease, and the levels were shown to correlate with the number of GAD-reactive gamma-interferon-producing T cells in patients positive for GAD autoantibodies (Shimada, A. et al. (2001) Diabetes Care 24:510-515). In a separate study, serum IP-10 levels were found to be increased in patients with newly diagnosed disease and in patients at high risk for the disease, and IP-10 concentrations correlated with IFN-gamma levels (Nicoletti, F. et al. (2002) Diabetologia 45:1107-1110). Moreover, beta cells have been demonstrated to secrete IP-10, leading to chemoattraction of T cells, and mice deficient in CXCR3 have been shown to have delayed onset of Type I diabetes (Frigerio, S. et al. (2002) Nature Medicine 8:1414-1420).

Accordingly, in another embodiment, the anti-IP-10 antibodies of the invention can be used in the treatment of Type I diabetes by administering the antibody to a subject in need of treatment. The antibody can be used alone or in combination with other anti-diabetic agents, such as insulin.

F. Inflammatory Skin Disorders

IP-10 expression has been shown to be associated with a variety of inflammatory skin disorders. For example, IP-10 has been detected in keratinocytes and the dermal infiltrate from active psoriatic plaques (Gottlieb, A. B. et al. (1988) J. Exp. Med. 168:941-948). Moreover, CXCR3 is expressed by dermal CD3+ lymphocytes, suggesting that CXCR3 is involved in T lymphocyte trafficking to the psoriatic dermis (Rottman, J. B. et al. (2001) Lab. Invest. 81:335-347). Accordingly, in another embodiment, the anti-IP-10 antibodies of the invention can be used in the treatment of psoriasis by administering the antibody to a subject in need of treatment. The antibody can be used alone or in combination with other agents or treatments, such as topical treatments (e.g., steroids, coal tar, calcipotriene, tazarotene, anthralin, salicylic acid), phototherapy, systemic medications (e.g., methotrexate, oral retinoids, cyclosporine, fumaric acid esters) and/or biologic drugs (e.g., alefacept, efalizumab).

Lichen planus, a chronic inflammatory disease of the skin and oral mucosa, has been shown to be associated with infiltrating CD4+ and CD8+ T cells that express CXCR3 and, moreover, the CD8+ infiltrating cytolytic T cells have to shown to have IP-10 in their cytolytic granules and the lesional keratinocytes have been shown to overexpress IP-10 (Iijima, W. et al. (2003) Am. J. Pathol. 163:261-268). Accordingly, in another embodiment, the anti-IP-10 antibodies of the invention can be used in the treatment of lichen planus by administering the antibody to a subject in need of treatment. The antibody can be used alone or in combination with other agents or treatments, such as anti-inflammatory agents, anti-histamines, corticosteroids and light therapy.

IP-10 expression has been shown to be elevated in other inflammatory skin disorders, such as chronic discoid lupus erythematosus and Jessner's lymphocytic infiltration of the skin (Flier, J. et al. (2001) J. Pathol. 194:398-405). Accordingly, the anti-IP-10 antibodies of the invention can be used in the treatment of these inflammatory skin disorders by administering the antibody to a subject in need of treatment. The antibody can be used alone or in combination with other agents or treatments, as described above.

G. Autoimmune Thyroid Disease

Both IP-10 and CXCR3 have been shown to be expressed in the thyroid gland of patients suffering from Graves' Disease (GD), but not to be expressed (or poorly expressed) in normal thyroid tissue, and expression was highest in patients with recent onset GD (Romagnani, P. et al. (Am. J. Pathol. 161:195-206). IP-10 also has been shown to be expressed in thyroid tissue of patients suffering from Hashimoto's thyroiditis (Kemp, E. H. et al. (2003) Clin. Endocrinol. 59:207-213). Accordingly, in another embodiment, the anti-IP-10 antibodies of the invention can be used in the treatment of autoimmune thyroid disease, including Graves' Disease and Hashimoto's thyroiditis, by administering the antibody to a subject in need of treatment. The antibody can be used alone or in combination with other agents or treatments, such as anti-thyroid drugs, radioactive iodine and subtotal thyroidectomy.

H. Sjogren's Syndrome

The expression of IP-10 mRNA has been shown to be significantly upregulated in the salivary glands of patients with Sjogren's syndrome (SS), with expression being most prominent in the ductal epithelium adjacent to lymphoid infiltrates (see e.g., Ogawa, N. et al. (2002) Arthritis Rheum. 46:2730-2741). Accordingly, in another embodiment, the anti-IP-10 antibodies of the invention can be used in the treatment of Sjogren's Syndrome by administering the antibody to a subject in need of treatment. The antibody can be used alone or in combination with other anti-SS agents, such as artificial lubricants (e.g., preservative-free artificial tears, artificial salivas, unscented skin lotions, saline nasal sprays, and vaginal lubricants), Lacriserts® for treatment of dry eyes, pilocarpine hydrochloride (Salagen®) and ceyimeline (Eyoxac®) for treatment of dry mouth, non-steroidal anti-inflammatory drugs (NSAIDs), steroids and immunosuppressive drugs.

I. Pulmonary Inflammation

IP-10 expression has been examined in a mouse model of allergic asthma, with the results demonstrating that IP-10 is upregulated in the lungs after allergen challenge and that overexpression of IP-10 was associated with increased airway hyperactivity, eosinophilia, increased IL-4 levels and recruitment of CD8+ lymphocytes (Medoff, B. D. et al. (2002) J. Immunol. 168:5278-5286). Moreover, smokers who develop chronic obstructive pulmonary disease (COPD) have been shown to express IP-10 in their bronchiolar epithelium (Saetta, M. et al. (2002) Am. J. Respir. Crit. Care Med. 165:1404-1409). Still further, high levels of IP-10 have been demonstrated in the bronchoalveolar lavage fluid of patients with pulmonary sarcoidosis and lymphocytic alveolitis (Agostini, C. et al. (1998) J. Immunol. 161:6413-6420).

Accordingly, in another embodiment, the anti-IP-10 antibodies of the invention can be used in the treatment of disease characterized by pulmonary inflammation, such as asthma, COPD, pulmonary sarcoidosis or lymphocytic alveolitis, by administering the antibody to a subject in need of treatment. The antibody can be used alone or in combination with other agents for reducing pulmonary inflammation, such as cromolyn sodium, nedocromil sodium, inhaled corticosteroids, systemic (e.g., oral) corticosteroids, short acting beta antagonists, short acting bronchodilators, long acting beta antagonists or agonists (oral or inhaled), leukotriene modifiers, theophylline and oxygen therapy.

J. Transplant Rejection

IP-10 has been shown to play a role in rejection of transplanted tissue. For example, treatment of mice with neutralizing anti-IP-10 antibodies increased the survival of small bowel allografts and reduced accumulation of host Tcells and NK cells in the lamina propria (Zhang, Z. et al. (2002) J. Immunol. 168:3205-3212). Furthermore, in mice receiving pancreatic islet allografts, anti-IP-10 antibody treatment also resulted in increased allograft survival and decreased lymphocytic graft infiltration (Baker, M. S. et al. (2003) Surgery 134:126-133). Additionally, cardiac allografts, but not normal hearts, were shown to express IP-10 and CXCR3, and elevated IP-10 levels were associated with cardiac allograft vasculopathy (Zhao, D. X. et al. (2002) J. Immunol. 169:1556-1560). CXCR3 and IP-10 also have been shown to be expressed by inflammatory cells infiltrating lung allografts (Agostini, C. et al. (2001) Am J. Pathol. 158:1703-1711). Neutralization of CXCR3 or IP-10 in vivo was shown to attenuate bronchiolitis obliterans syndrome (BOS), the major limitation to survival for lung transplant recipients, in a murine lung transplant model (Belperio, J. A. et al. (2002) J. Immunol. 169:1037-1049).

In view of the foregoing, the invention also provides a method of inhibiting transplant rejection by administering an anti-IP-10 antibody of the invention to a transplant recipient in need of treatment. Examples of tissue transplants that can be treated include, but are not limited to, liver, lung (e.g., treatment of BOS), kidney, heart, small bowel, and pancreatic islet cells. The antibody can be used alone or in combination with other agents for inhibiting transplant rejection, such as immunosuppressive agents (e.g., cyclosporine, azathioprine, methylprednisolone, prednisolone, prednisone, mycophenolate mofetil, sirilimus, rapamycin, tacrolimus), anti-infective agents (e.g., acyclovir, clotrimazole, ganciclovir, nystatin, trimethoprimsulfarnethoxazole), diuretics (e.g., bumetanide, furosemide, metolazone) and ulcer medications (e.g., cimetidine, famotidine, lansoprazole, omeprazole, ranitidine, sucralfate).

K. Spinal Cord Injury

Traumatic injury to the spinal cord leads to infiltration of inflammatory cells. IP-10 has been shown to play a central role in secondary degeneration following spinal cord injury (Gonzalez et al. (2003) Exp. Neuro/0.184:456-463; see also PCT patent publication WO 03/06045). IP-10 has been shown to be significantly elevated in the contused rat spinal cords 6 and 12 hours postinjury (McTigue, D. M. et al. (1998) J. Neurosci. Res. 53:368-376) and in the injured mouse spinal cord 6 hours post injury (Gonzalez et al. (2003) supra). Accordingly, inhibition of IP-10 activity after spinal cord injury has been shown to be useful in reducing infiltration of inflammatory cells and thus reducing secondary tissue damage to inflammation. Inhibition may also reduce infiltration of inflammatory cells, decrease secondary degeneration and improve recovery following traumatic brain injury and stroke. Thus, the invention also provides a method of treating spinal cord injury and brain injury (e.g., stroke) in a subject in need of treatment comprising administering to the subject an anti-IP-10 antibody of the invention. The antibody can be used alone or in combination with other agents, such as other anti-inflammatory agents.

L. Neurodegenerative Diseases

IP-10 and CXCR3 expression within the central nervous system has been found to be upregulated in association with pathological changes associated with Alzheimer's Disease (AD) (Xia, M. Q. and Hyman, D. T. (1999) J. Neurovirol. 5:32-41). Within AD brains, CXCR3 was shown to be expressed constitutively on neurons and neuronal processes in various cortical and subcortical regions and IP-10 was shown to be expressed in astrocytes and its level was markedly elevated as compared to normal brains (Xia, M. Q. et al. (2000) J. Neuroimmunol. 108:227-235). Accordingly, the antibodies of the invention can be used in the treatment of neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease, by administering to a subject in need of treatment the anti-IP-10 antibody, alone or in combination with other therapeutic agents. Examples of agents with which the anti-IP-10 antibody can be combined for Alzheimer's disease treatment include cholinesterase inhibitors (donepezil, rivastigmine, galantamine, tacrine) and vitamin E. An example of an agent with which the anti-IP-10 antibody can be combined for Parkinson's disease treatment is levodopa.

M. Gingivitis

Marginal periodontitis is associated with inflamed gingival tissue. Cells producing IP-10 have been found in inflamed human gingival tissue, as well as cells expressing the CXCR3 receptor (Kabashima, H. et al. (2002) Cytokine 20:70-77). Accordingly, in another embodiment, the anti-IP-10 antibodies of the invention can be used in the treatment of gingivitis by administering the antibody to a subject in need of treatment. The antibody can be used alone or in combination with other agents or treatments, such as anti-gingival mouthwashes (e.g., antibiotic mouthwashes), periodontal scaling and root planing and periodontal surgery.

N. Gene Therapy-Associated Inflammation

Replication-deficient adenoviruses, used as adenoviral vectors used in gene therapy, can cause acute injury and inflammation in tissues infected by the viral vectors. Such adenoviral vectors have been shown to induce the expression of IP-10 through capsid-dependent activation of NFkB (Borgland, S. L. et al. (2000) J. Virol. 74:3941-3947). Accordingly, the anti-IP-10 antibodies of the invention can be used to inhibit IP-10-induced injury and/or inflammation during gene therapy treatment that utilizes a viral vector, such as an adenoviral vector, that stimulates unwanted production of IP-10.

O. Diseases of Angiogenesis

IP-10 has been shown to inhibit angiogenesis in vitro and in vivo (Strieter et al. (1995) Biochem. Biophys. Res. Commun. 210:51-57; Angiolillo et al. (1995) J. Exp. Med. 182:155-162; Luster et al. (1995) J. Exp. Med. 182:219-231). Angiogenesis plays a crucial role in many disease processes, such as the healing response to trauma. For example, vasculature within the injured spinal cord remains in a state of active remodeling until at least 28 days post injury (Popovich et al. (1997) J. Comp. Neurol. 377:443-464).

IP-10 is thought to exert its angiostatic effects through the inhibition of endothelial cell growth and chemotaxis. It does this through its heparin-binding motif as well as through a receptor-mediated mechanism. Through its heparin-binding motif it prevents the angiogenic factors FGF-2 and VEFG165 from binding to their receptors. It also exerts its effects through a receptor-mediated process. The receptor for IP-10, CXCR3, is alternatively spliced to produce the two known variations CXCR3A and CXCR3B. IP-10 binding to the CXCR3A receptor leads to proliferation and chemotaxis of the target cell, whereas IP-10 binding to the CXCR3B receptor has the opposite effect of inhibition of growth and chemotaxis. It is through the CXCR3B receptor that IP-10 acts as an angiostatic factor (Lasagni et al. (2003) J. Exp. Med. 197:1537-1549).

In view of the foregoing, the anti-IP-10 antibodies of the invention can be used in the treatment of diseases requiring angiogenesis, for example where the angiostatic behaviour of IP-10 delays or prevents healing and exacerbates the disease process. Such diseases include: 1) aberrant physiological neovascularization, which may impact wound healing, the female estrus cycle, pregnancy, exercise-induced hypertrophy and the like; 2) indications that may require stimulation of neovascularization, including induction of collateral vessel formation (including myocardial ischemia, peripheral ischemia, cerebral ischemia), coronary artery disease, peripheral vascular disease, stroke, wound healing, engraftment subsequent to organ transplantation such as islet cell transplantation, fracture and tendon repair, reconstructive surgery, tissue engineering, restenosis, hair loss, decubitus and stasis ulcers, gastrointestinal ulcers, placental insufficiency, aseptic necrosis, pulmonary and systemic hypertension, vascular dementia, Alzheimer's Disease, cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL); thyroid psuedocyst and lymphoedema; and 3) indications that may require vascular remodeling, including vascular malformations, psoriasis, and pre-eclampsia. The antibodies of the invention can be used alone or in combination with other angiogenesis inducing agents.

P. Inflammatory Kidney Disease

The CXCR3 receptor has been reported to be expressed by mesangial cells of patients with IgA nephropathy, membranoproliferative glomerulonephritis or rapidly progressive glomerulonephritis (Romagnani, P. et al. (1999) J. Am. Soc. Nephrol. 10:2518-2526). Furthermore, in a mouse model of nephrotoxic nephritis, IP-10 mRNA levels were increased six-fold in the cortex of nephritic kidneys 7 days after induction of nephritis (Schadde, E. et al. (2000) Nephrol. Dial. Transplant. 15:1046-1053). Still further, high levels of IP-10 expression were observed in kidney biopsy specimens of human patients with glomerulonephritis as compared to normal kidneys (Romagnani, P. et al. (2002) J. Am. Soc. Nephrol. 13:53-64). Accordingly, the anti-IP-10 antibodies of the invention can be used in the treatment of inflammatory kidney disease, including IgA nephropathy, memranoproliferative glomerulonephritis and rapidly progressive glomerulonephritis. The antibodies of the invention can be used alone or in combination with other agents or treatments used in the treatment of glomerulonephritis, such as antibiotics, diuretics, high blood pressure medications and dialysis.

Q. Atherosclerosis

IP-10 has been shown to be a mitogenic and chemotactic factor for vascular smooth muscle, which are important features of smooth muscle cells for their contribution to the pathogenesis of atherosclerosis (Wang, X. et al. (1996) J. Biol. Chem. 271:24286-24293). IP-10 also has been shown to be induced in smooth muscle cells after treatment with LPS or interferon gamma, and was also induced in the rat carotid artery after balloon angioplasty (Wang, X. et al. (1996) supra). Moreover, IP-10 has been demonstrated to be expressed in atheroma-associated endothelial cells, smooth muscle cells and macrophages, suggesting a role for IP-10 in recruitment and retention of activated T cells that have been observed within vascular wall lesions during atherogenesis (Mach, F. et al. (1999) J. Clin. Invest. 104:1041-1050). Accordingly, the anti-IP-10 antibodies of the invention can be used in the treatment or prevention of atherosclerosis. The antibodies can be used alone or in combination with other agents or treatments used in the treatment of atherosclerosis, such high blood pressure medications and cholesterol-lowering drugs.

R. Viral Infections

IP-10 may be upregulated in various viral infections and may play a beneficial role in recruiting activated T cells to fight the viral infection. In certain instances, however, production of IP-10 during viral infection may lead to detrimental effects and thus, the IP-10 activity may be unwanted and it may be desirable to inhibit IP-10 activity in such viral infections using an anti-IP-10 antibody of the invention.

For example, IP-10 has been shown to stimulate replication of human immunodeficiency virus (HIV) in monocyte-derived macrophages and peripheral blood lymphocytes (Lane, B. R. et al. (2003) Virology 307:122-134). Furthermore, IP-10 levels are elevated in cerebrospinal fluid and brain of HIV-infected patients and in the central nervous system of HIV gp120-transgenic mice (Asensio, V. C. et al. (2001) J. Virol. 75:7067-7077).

IP-10 levels also have been shown to be elevated in patients with chronic persistent hepatitis C virus (HCV) and in patients with chronic active hepatitis (Narumi, S. et al. (1997) J. Immunol. 158:5536-5544). In HCV-infected livers, IP-10 was shown to be expressed by hepatocytes but not by other cell types within the liver, and a significantly higher proportion of CXCR3 positive T cells was found in the liver as compared to blood (Harvey, C. E. et al. (2003) J. Leukoc. Biol. 74:360-369).

Increased secretion of IP-10 has been shown to be associated with the inflammatory response to acute ocular herpes simplex virus type I (HSV-1) infection in mice, and treatment of HSV-1 infected mice with anti-IP-10 antibodies was shown to reduce mononuclear cell infiltration into the corneal stroma, reduce corneal pathology, and inhibit progression of the virus from the corneal stroma to the retina during acute infection (Carr, D. J. et al. (2003) J. Virol. 77:10037-10046).

IP-10 expression also has been shown to be expressed in viral meningitis. IP-10 was demonstrated to be present in the CSF of patients with viral meningitis and to be responsible for chemotactic activity on neutrophils, peripheral blood mononuclear cells and activated T cells (Lahrtz, F. et al. (1997) Eur. J. Immunol. 27:2484-2489; Lahrtz, F. et al. (1998) J. Neuroimmunol. 85:33-43).

In view of the foregoing, the anti-IP-10 antibodies of the invention can be used in the treatment of viral infections involving unwanted IP-10 activity by administering the antibody to a subject in need of treatment. Non-limiting examples of viral infections that can be treated include HIV (e.g., HIV-induced encephalitis), HCV, HSV-1, viral meningitis and Severe Acute Respiratory Syndrome (SARS). The antibody can be used alone or in combination with other anti-viral agents, such as, for HIV infection, nucleoside/nucleotide reverse transciptase inhibitors, non-nucleoside reverse transciptase inhibitors and/or protease inhibitors (and combinations thereof), for HCV infection, interferon alpha 2a, pegylated interferon alpha 2a, and/or ribavirin, and for HSV-1 infection, acyclovir, valacyclovir and/or famciclovir.

S. Bacterial Infections.

Bacterial infections induce IP-10 production in affected cells (see Gasper, N. A. et al. (2002) Infect Immun. 70:4075-82.) Bacterial meningitis is also specifically known to invoke IP-10 expression (Lapinet, J. A. et al. (2000) Infect Immun. 68:6917-23). IP-10 is also produced by testicular somatic cells of seminiferous tubules, in a bacterial infection model, strongly indicating a likely role of these chemokines in the accumulation of neutrophils and T lymphocytes during testicular inflammation, which is classically observed in the pathogenesis of bacterial infections (Aubry, F. et al. (2000) Eur Cytokine Netw. 11:690-8).

In view of the foregoing, the anti-IP-10 antibodies of the invention can be used in the treatment of bacterial infections involving unwanted IP-10 activity by administering the antibody to a subject in need of treatment. Examples of bacterial infections include, but are not limited to, bacterial meningitis and bacterial pneumonia. The antibody can be used alone or in combination with other antibacterial agents, such as antibiotics.

The present invention is further illustrated by the following examples which should not be construed as further limiting. The contents of all figures and all references, patents and published patent applications cited throughout this application are expressly incorporated herein by reference.

Example 1: Generation of Human Monoclonal Antibodies Against IP-10

Antigen

Purified recombinant human IP10 derived from E. coli (PeproTech, Inc., Cat number: 300-12), or purified recombinant human IP10 conjugated to keyhole limpet hemocyanin (KLH), was used as the antigen

Transgenic HuMab and KM Mice

Fully human monoclonal antibodies to IP10 were prepared using HCo7, HCo12 and HCo17 strains of HuMab transgenic mice and the KM strain of transgenic transchromosomic mice, each of which express human antibody genes. In each of these mouse strains, the endogenous mouse kappa light chain gene has been homozygously disrupted as described in Chen et al. (1993) EMBO J. 12:811-820 and the endogenous mouse heavy chain gene has been homozygously disrupted as described in Example 1 of PCT Publication WO 01/09187. Each of these mouse strains carries a human kappa light chain transgene, KCo5, as described in Fishwild et al. (1996) Nature Biotechnology 14:845-851. The HCo7 strain carries the HCo7 human heavy chain transgene as described in U.S. Pat. Nos. 5,545,806; 5,625,825; and 5,545,807. The HCo12 strain carries the HCo12 human heavy chain transgene as described in Example 2 of PCT Publication WO 01/09187. The HCo17 stain carries the HCo17 human heavy chain transgene as described in Example 8 below. The KM strain contains the SC20 transchromosome as described in PCT Publication WO 02/43478.

HuMab and KM Immunizations:

To generate fully human monoclonal antibodies to IP10, HuMab mice and KM mice were immunized with purified recombinant IP10 derived from E. coli or IP 10-KLH conjugate as antigen. General immunization schemes for HuMab mice are described in Lonberg, N. et al (1994) Nature 368(6474): 856-859; Fishwild, D. et al. (1996) Nature Biotechnology 14: 845-851 and PCT Publication WO 98/24884. The mice were 6-16 weeks of age upon the first infusion of antigen. A purified recombinant preparation (5-50 μg) of IP10 antigen (e.g., purified from transfected E. coli cells expressing IP 10) was used to immunize the HuMab mice and KM mice intraperitonealy, subcutaneously (Sc) or via footpad injection.

Transgenic mice were immunized twice with antigen in complete Freund's adjuvatnt or Ribi adjuvant either intraperitonealy (IP), subcutaneously (Sc) or via footpad (FP), followed by 3-21 days IP, Sc or FP immunization (up to a total of 11 immunizations) with the antigen in incomplete Freund's or Ribi adjuvant. The immune response was monitored by retroorbital bleeds. The plasma was screened by ELISA (as described below), and mice with sufficient titers of anti-IP 10 human immunogolobulin were used for fusions. Mice were boosted intravenously with antigen 3 and 2 days before sacrifice and removal of the spleen. Typically, 10-35 fusions for each antigen were performed. Several dozen mice were immunized for each antigen. A total of 82 mice of the HCo7, HCo12, HCo17 and KM mice strains were immunized with IP10.

Selection of HuMab or KM Mice Producing Anti-IP 10 Antibodies:

To select HuMab or KM mice producing antibodies that bound IP10, sera from immunized mice was tested by ELISA as described by Fishwild, D. et al. (1996). Briefly, microtiter plates were coated with purified recombinant IP10 from E. coli at 1-2 μg/ml in PBS, 50 μl/wells incubated 4° C. overnight then blocked with 200 μl/well of 5% chicken serum in PBS/Tween (0.05%). Dilutions of plasma from IP 10-immunized mice were added to each well and incubated for 1-2 hours at ambient temperature. The plates were washed with PBS/Tween and then incubated with a goat-anti-human IgG Fc polyclonal antibody conjugated with horseradish peroxidase (HRP) for 1 hour at room temperature. After washing, the plates were developed with ABTS substrate (Sigma, A-1888, 0.22 mg/ml) and analyzed by spectrophotometer at OD 415-495. Mice that developed the highest titers of anti-IP10 antibodies were used for fusions. Fusions were performed as described below and hybridoma supernatants were tested for anti-IP10 activity by ELISA.

Generation of Hybridomas Producing Human Monoclonal Antibodies to IP10:

The mouse splenocytes, isolated from the HuMab mice and KM mice, were fused with PEG to a mouse myeloma cell line based upon standard protocols. The resulting hybridomas were then screened for the production of antigen-specific antibodies. Single cell suspensions of splenic lymphocytes from immunized mice were fused to one-fourth the number of SP2/0 nonsecreting mouse myeloma cells (ATCC, CRL 1581) with 50% PEG (Sigma). Cells were plated at approximately 1×10⁵/well in flat bottom microtiter plate, followed by about two week incubation in selective medium containing 10% fetal bovine serum, 10% P388D1 (ATCC, CRL TIB-63) conditioned medium, 3-5% origen (IGEN) in DMEM (Mediatech, CRL 10013, with high glucose, L-glutamine and sodium pyruvate) plus 5 mM HEPES, 0.055 mM 2-mercaptoethanol, 50 mg/ml gentamycin and 1×HAT (Sigma, CRL P-7185). After 1-2 weeks, cells were cultured in medium in which the HAT was replaced with HT. Individual wells were then screened by ELISA (described above) for human anti-IP 10 monoclonal IgG antibodies. Once extensive hybridoma growth occurred, medium was monitored usually after 10-14 days. The antibody secreting hybridomas were replated, screened again and, if still positive for human IgG, anti-IP 10 monoclonal antibodies were subcloned at least twice by limiting dilution. The stable subclones were then cultured in vitro to generate small amounts of antibody in tissue culture medium for further characterization.

Hybridoma clones 1D4, 1E1, 2G1, 3C4, 6A5, 6A8, 6B10, 7C10, 8F6, 10A12 and 13C4 were selected for further analysis.

Example 2: Structural Characterization of Human Monoclonal Antibodies Against IP-10

The cDNA sequences encoding the heavy and light chain variable regions of the 1D4, 1E1, 2G1, 3C4, 6A5, 6A8, 6B10, 7C10, 8F6, 10A12 and 13C4 monoclonal antibodies were obtained from the corresponding hybridomas using standard PCR techniques and were sequenced using standard DNA sequencing techniques. In cases where DNA sequencing alone was not sufficient to unambiguously determine the antibody structure, protein analysis (e.g., N-terminal amino acid analysis and mass spectroscopy) was also performed and the results compared to the DNA sequence analysis to thereby determine the correct antibody structure. The structural analysis results are as follows:

The nucleotide and amino acid sequences of the heavy chain variable region of 1D4 are shown in FIG. 1A and in SEQ ID NOs: 99 and 35, respectively. The nucleotide and amino acid sequences of the light chain variable region of 1D4 are shown in FIG. 1B and in SEQ ID NOs: 110 and 84, respectively.

The nucleotide and amino acid sequences of the heavy chain variable region of 1E1 are shown in FIG. 2A and in SEQ ID NOs: 100 and 36, respectively. The nucleotide and amino acid sequences of the light chain variable region of 1E1 are shown in FIG. 2B and in SEQ ID NOs: 111 and 85, respectively.

The nucleotide and amino acid sequences of the heavy chain variable region of 2G1 are shown in FIG. 3A and in SEQ ID NOs: 101 and 37, respectively. The nucleotide and amino acid sequences of the light chain variable region of 2G1 are shown in FIG. 3B and in SEQ ID NOs: 112 and 86, respectively.

The nucleotide and amino acid sequences of the heavy chain variable region of 3C4 are shown in FIG. 4A and in SEQ ID NOs: 102 and 38, respectively. The nucleotide and amino acid sequences of the light chain variable region of 3C4 are shown in FIG. 4B and in SEQ ID NOs: 113 and 87, respectively.

The nucleotide and amino acid sequences of the heavy chain variable region of 6A5 are shown in FIG. 5A and in SEQ ID NOs: 103 and 39, respectively. The nucleotide and amino acid sequences of the light chain variable region of 6A5 are shown in FIG. 5B and in SEQ ID NOs: 114 and 88, respectively.

The nucleotide and amino acid sequences of the heavy chain variable region of 6A8 are shown in FIG. 6A and in SEQ ID NOs: 104 and 40, respectively. The nucleotide and amino acid sequences of the light chain variable region of 6A8 are shown in FIG. 6B and in SEQ ID NOs: 115 and 89, respectively.

The nucleotide and amino acid sequences of the heavy chain variable region of 6B10 are shown in FIG. 7A and in SEQ ID NOs: 105 and 41, respectively. The nucleotide and amino acid sequences of the light chain variable region of 6B10 are shown in FIG. 7B and in SEQ ID NOs: 116 and 90, respectively.

The nucleotide and amino acid sequences of the heavy chain variable region of 7C10 are shown in FIG. 8A and in SEQ ID NOs: 106 and 42, respectively. The nucleotide and amino acid sequences of the light chain variable region of 7C10 are shown in FIG. 8B and in SEQ ID NOs: 117 and 91, respectively.

The nucleotide and amino acid sequences of the heavy chain variable region of 8F6 are shown in FIG. 9A and in SEQ ID NOs: 107 and 43, respectively. The nucleotide and amino acid sequences of the light chain variable region of 8F6 are shown in FIG. 9B and in SEQ ID NOs: 118 and 92, respectively.

The nucleotide and amino acid sequences of the heavy chain variable region of 10A12 are shown in FIG. 10A and in SEQ ID NOs: 108 and 44, respectively. The nucleotide and amino acid sequences of the light chain variable region of 10A12 are shown in FIG. 10B and in SEQ ID NOs: 119 and 93, respectively.

The nucleotide and amino acid sequences of the heavy chain variable region of 13C4 are shown in FIG. 11A and in SEQ ID NOs: 109 and 46, respectively. The nucleotide and amino acid sequences of the light chain variable region of 13C4 are shown in FIG. 11B and in SEQ ID NOs: 120 and 94, respectively.

Comparison of the 1D4, 1E1, 2G1, 6A5, 6A8, 7C10 and 10A12 heavy chain immunoglobulin sequences to the known human germline immunoglobulin heavy chain sequences demonstrated that these antibody heavy chains utilizes a V_(H) segment from human germline V_(H) 3-33. The alignment of the 1D4, 1E1, 2G1, 6A5, 6A8, 7C10 and 10A12 V_(H) sequences to the germline V_(H) 3-33 sequence (SEQ ID NO: 47) is shown in FIG. 12. Further analysis of the 1D4, 1E1, 2G1, 6A5, 6A8, 7C10 and 10A12 VH sequences using the Kabat system of CDR region determination led to the delineation of the heavy chain CDR1, CDR2 and CD3 regions as shown in FIGS. 1A, 2A, 3A, 5A, 6A, 8A and 10A, respectively.

Comparison of the 6B10 and 8F6 heavy chain immunoglobulin sequences to the known human germline immunoglobulin heavy chain sequences demonstrated that these antibody heavy chains utilizes a V_(H) segment from human germline V_(H) 3-30.3. The alignment of the 6B10 and 8F6 V_(H) sequences to the germline V_(H) 3-33 sequence (SEQ ID NO: 48) is shown in FIG. 13. Further analysis of the 6B10 and 8F6 VH sequences using the Kabat system of CDR region determination led to the delineation of the heavy chain CDR1, CDR2 and CD3 regions as shown in FIGS. 7A and 9A, respectively.

Comparison of the 3C4 heavy chain immunoglobulin sequence to the known human germline immunoglobulin heavy chain sequences demonstrated that this antibody heavy chain utilizes a V_(H) segment from human germline V_(H) 5-51. The alignment of the 3C4 V_(H) sequence to the germline V_(H) 5-51 sequence (SEQ ID NO: 49) is shown in FIG. 14. Further analysis of the 3C4 VH sequence using the Kabat system of CDR region determination led to the delineation of the heavy chain CDR1, CDR2 and CD3 regions as shown in FIG. 4A.

Comparison of the 13C4 heavy chain immunoglobulin sequence to the known human germline immunoglobulin heavy chain sequences demonstrated that this antibody heavy chain utilizes a V_(H) segment from human germline V_(H) 4-61. The alignment of the 13C4 V_(H) sequence to the germline V_(H) 4-61 sequence (SEQ ID NO: 50) is shown in FIG. 15. Further analysis of the 13C4 VH sequence using the Kabat system of CDR region determination led to the delineation of the heavy chain CDR1, CDR2 and CD3 regions as shown in FIG. 11A.

Comparison of the 1D4, 2G1, 6A5, 6A8, 10A12 and 13C4 light chain immunoglobulin sequences to the known human germline immunoglobulin light chain sequences demonstrated that these antibody light chains utilizes a V_(L) segment from human germline V_(k) A27. The alignment of the 1D4, 2G1, 6A5, 6A8, 10A12 and 13C4 V_(L) sequences to the germline V_(K) A27 sequence (SEQ ID NO: 95) is shown in FIG. 16. Further analysis of the 1D4, 2G1, 6A5, 6A8, 10A12 and 13C4 V_(L) sequences using the Kabat system of CDR region determination led to the delineation of the light chain CDR1, CDR2 and CD3 regions as shown in FIGS. 1B, 3B, 5B, 6B, 10B and 11B, respectively.

Comparison of the 1E1, 6B10 and 8F6 light chain immunoglobulin sequences to the known human germline immunoglobulin light chain sequences demonstrated that these antibody light chains utilizes a V_(L) segment from human germline V_(k) L6. The alignment of the 1E1, 6B10 and 8F6 V_(L) sequences to the germline V_(K) L6 sequence (SEQ ID NO: 96) is shown in FIG. 17. Further analysis of the 1E1, 6B10 and 8F6 V_(L) sequences using the Kabat system of CDR region determination led to the delineation of the light chain CDR1, CDR2 and CD3 regions as shown in FIGS. 2B, 7B and 9B, respectively.

Comparison of the 3C4 light chain immunoglobulin sequence to the known human germline immunoglobulin light chain sequences demonstrated that the 3C4 light chain utilizes a V_(L) segment from human germline V_(k) L18. The alignment of the 3C4 V_(L) sequence to the germline V_(k) L18 sequence (SEQ ID NO: 97) is shown in FIG. 18. Further analysis of the 3C4 V_(L) sequence using the Kabat system of CDR region determination led to the delineation of the light chain CDR1, CDR2 and CD3 regions as shown in FIG. 4B.

Comparison of the 7C10 light chain immunoglobulin sequence to the known human germline immunoglobulin light chain sequences demonstrated that the 7C10 light chain utilizes a V_(L) segment from human germline V_(k) L15. The alignment of the 7C10 V_(L) sequence to the germline V_(k) L15 sequence (SEQ ID NO: 98) is shown in FIG. 19. Further analysis of the 7C10 V_(L) sequence using the Kabat system of CDR region determination led to the delineation of the light chain CDR1, CDR2 and CD3 regions as shown in FIG. 8B.

Example 3: Characterization of Binding Specificity and Binding Kinetics of Anti-IP-10 Human Monoclonal Antibodies

In this example, binding affinity, binding kinetics and binding specificity of anti-IP-10 antibodies were examined by Biacore analysis. Also, binding specificity and cross-competition was examined by ELISA.

Biacore Analysis

Anti-IP-10 antibodies were characterized for affinities and binding kinetics by Biacore analysis (Biacore AB, Uppsala, Sweden). E. coli-expressed, purified recombinant human IP-10 (R& D Systems) was coupled to the CMS sensor chip @ 97 RU using the EDC/NHS coupling protocol provided by Biacore AB. Binding was measured by flowing the antibody in HBS EP buffer (provided by Biacore AB) at concentrations from 33-267 nM at a flow rate of 40 μl/min. The antigen-antibody association kinetics was followed for 5 minutes and the dissociation kinetics was followed for 8 minutes. The association and dissociation curves were fit to a 1:1 Langmuir binding model using BIAevaluation software (Biacore AB). Data corresponding to the initial few dozen seconds for association and dissociation phases alone were considered for curve fitting to minimize the effect of avidity. The experiments were performed at both 25° C. and 37° C. The K_(D), k_(on) and k_(off) values that were determined are shown in Table 1 for binding at 25° C. and in Table 2 for binding at 37° C.:

TABLE 1 Binding Characterization at 25° C. with Human IP-10 Affinity On rate Off rate K_(D) × 10⁻⁹ K_(on) × 10⁴ K_(off) × 10⁻⁵ Clone ID (M) (1/Ms) (1/s) 7C10 0.02 1.70 0.04 10A12 0.53 3.83 2.02 8F6 0.81 23.3 19.0 10A12S 0.88 3.68 3.24 6A5 1.20 3.11 3.64 6A5 Batch 2* 0.96 3.20 3.10 1D4 1.20 8.40 10.20 6B10 1.78 9.50 17.2 2G1 1.90 3.78 0.75 *6A5 Batch 2 is an independent sample of purified antibody from the 6A5 hybridoma supernatant as compared to sample 6A5.

TABLE 2 Binding Characterization at 37° C. with Human IP-10 Affinity On rate Off rate K_(D) × 10⁻⁹ K_(on) × 10⁴ K_(off) × 10⁻⁵ Clone ID (M) (1/Ms) (1/s) 7C10 0.016 5.27 0.08 10A12 0.34 11.1 3.81 8F6 0.78 34.7 27.0 10A12S 0.49 9.10 4.43 6A5 0.70 10.2 7.15 6A5 Batch 2 0.74 8.41 6.26 1D4 1.15 16.6 19.2 6B10 2.54 19.9 50.4 2G1 0.34 14.8 4.97

The half-life of the antibodies (in hours), as defined by the time taken for the dissociation of half of the antibody-antigen complex during the dissociation phase, was measured at 25° C. and 37° C. The values were determined by extension of the dissociation curves to get to the time required for the 50% reduction of the Y-axis of the dissociation sensogram. The results are shown below in Table 3:

TABLE 3 Half-Life of Antibodies at 25° C. and 37° C. Half-life (in Half-life (in Clone ID hours) at 25° C. hours) at 37° C. 2G1 25.67 3.87 10A12 9.53 5.05 10A12S 5.94 4.34 6A5 5.29 2.69 6A5 Batch 2 6.21 3.87 1D4 1.88 1.00 6B10 1.12 0.38 8F6 1.01 0.71

The cross-reactivity of the antibodies, at 25° C., with rhesus monkey IP-10, human MIG, human ITAC and mouse IP-10 was determined by Biacore analysis using the same methods as described above for human IP-10. Human MIG, human IP-10 and mouse IP-10 were obtained commercially (PeproTech, Rocky Hill, N.J.), whereas rhesus monkey IP-10 was made by recombinant expression and purified by standard methods. The antigens were conjugated to the CMS sensor chip @ 140 RUs (rhesus monkey IP-10), 457 RUs (human MIG), 206 RUs (human ITAC) and 150 RUs (mouse IP-10). Association sensograms were obtained by flowing antibodies in HBS EP buffer at a concentration of 133 nM for 5 minutes. The flow was then stopped and dissociation was monitored for 5 minutes. The association and dissociation curves were fit to a Langmuir binding model using BlAevaluation software (Biacore AB). The results of the cross-reactivity experiments are summarized below in Table 4:

TABLE 4 Anti-IP-10 Cross Reactivity with Various CXCR3 Ligands Rhesus IP-10 Human MIG Human ITAC Mouse IP-10 K_(D) × 10⁻⁹ K_(D) × 10⁻⁹ K_(D) × 10⁻⁹ K_(D) × 10⁻⁹ Clone ID (M) (M) (M) (M) 7C10 4.4 105.0 No binding 464.0 10A12 0.71 161.0 No binding No binding 8F6 0.81 No binding No binding No binding 10A12S 1.21 722.0 No binding No binding 6A5 1.06 No binding No binding No binding 6A5 Batch 2 1.23 No binding No binding No binding 1D4 0.94 No binding No binding No binding 6B10 2.01 15.4 51.5 105.0 2G1 0.26 70.1 No binding No binding ELISA Analysis

Additional experiments were performed using an ELISA assay to examine the antigenic cross-reactivity of the anti-IP-10 antibodies for human MIG, rhesus monkey IP-10 or mouse IP-10. The procedures used for the ELISA was as described above in Example 1 except that the microtiter plates were coated with 1 μg/ml of either recombinant human IP-10, human MIG (PeproTech, cat. #300-26), mouse IP-10 (PeproTech, cat. #250-16) or recombinant rhesus monkey IP-10. The results, expressed as EC₅₀ values (in ng/ml) are summarized below in Table 5:

TABLE 5 Anti-IP-10 Cross Reactivity by ELISA with Various CXCR3 Ligands Human IP-10 Monkey IP-10 Human MIG Mouse Clone ID (EC₅₀ ng/ml) (EC₅₀ ng/ml) (EC₅₀ ng/ml) IP-10 10A12 40 80 180 No binding 10A12S 4.9 15.6 380 No binding 2G1 30 30 45 No binding 6A5 35 90 No binding No binding 6A5 62 125 No binding No binding Batch 2 6B10 30 45 20 No binding 8F6 90 31 No binding No binding 1D4 25 62 No binding No binding

Cross-competition studies between the various anti-IP-10 antibodies were also performed by ELISA using biotinylated forms of 6A5 and 2G1 to determine whether the antibodies recognize different epitopes on IP-10. The procedure for competition ELISAs was similar to the ELISA described above in Example 1. Briefly, microtiter plates were coated with purified recombinant IP-10 from E. coli at 0.2 μg/ml in PBS, 50 μl/well and incubated 4° C. overnight. The wells then were blocked with 200 μl/well of 5% chicken serum in PBS/Tween (0.05%). Dilutions of purified human anti-human IP-10 antibodies (from 2 μg/ml to 3.91 ng/ml) were added to each well and incubated for 30 minutes at ambient temperature. The plates were washed with PBS/Tween and then incubated with 0.1 μg/ml of biotin-6A5 or biotin-2G1 for 30 minutes. The plates were then washed three times with PBS/Tween. After washing, phosphatase labeled streptavidin (KPL, Cat #: 15-30-00) was added at 1:2000 dilution in 5% chicken serum to each well and incubated for 1 hour at room temperature. After washing, the plates were developed with p-NPP substrate (Moss, Inc, lot 10274021) and analyzed by spectrophotometer at OD 405. As expected, unlabeled 2G1 could compete with biotin-2G1 for binding to IP-10 and, moreover, unlabeled 6A5, 7C10, 10A12, 10A12S, 6B10, 8F6 and 1D4 were each capable of competing the binding of biotin-2G1 to human IP-10. Similarly, unlabeled 6A5 could compete with biotin-6A5 for binding to IP-10 and, moreover, unlabeled 2G1, 7C10, 10A12, 10A12S, 6B10, 8F6 and 1D4 were each capable of competing the binding of biotin-6A5 to human IP-10. These results indicate that each of these antibodies have a binding specificity for the same epitope (or epitope group) of human IP-10.

Example 4: Inhibition of IP-10 Binding to CXCR3

In this example, the ability of anti-IP-10 antibodies to inhibit the binding of human IP-10 to its receptor, CXCR3, on receptor-expressing cells was examined First, a Scatchard analysis was performed for ¹²⁵I-IP-10 binding to 300.19 cells transfected to express CXCR3. The cells were grown in RPMI media containing 10% FCS and G418 selection. Prior to use, the cells were washed twice with Hank's Balanced Salt Solution (HBSS) at 4° C. and adjusted to 4×10⁷ cells/ml. Glass fiber plates (Millipore MultiScreen®, Cat. #MAFBN0B50) were blocked with 200 μl of a 0.1% polyethyleneimine solution one day prior to the experiment. On the day of the study, the blocking buffer was aspirated by using a Millipore manifold. The plates were washed three times with 200 μl of binding buffer (50 mM HEPES, pH 7.2, 1 mM CaCl₂, 5 mM MgCl₂, 0.5% BSA). Twenty-five microliters of binding buffer was added to each well followed by either 25 μl of 1000 fold excess unlabeled IP-10 or binding buffer. Twenty-five microliters of ¹²⁵I-IP-10 (Amersham, Cat. #IM332-25 μCi) at increasing concentrations was added, followed by 25 μl of cells at a density of 1×10⁶ cells per well. The plates were incubated on a plate shaker for 60 minutes at room temperature and washed three times with wash buffer (10 mM HEPES, pH 7.2, 0.5 M NaCl, 0.5% BSA) at a volume of 200 μl per wash. The plates were dried, 25 μl of scintillant was added and the plates were counted on a Wallac Microbeta Counter. Data were analyzed using Prism software and a K_(D) was calculated. A mean K_(D) of 0.231 nM was determined for receptor binding.

Next, the ability of the anti-IP-10 antibodies to inhibit the binding of 100 μM-¹²⁵I-hIP-10 to the CXCR3-expressing cells was examined. Competition assays were run in a similar manner to the experiment described above. Briefly, 25 μl of binding buffer was added to the glass fiber filter plates, followed by 25 μl of increasing concentrations of anti-IP-10 antibodies. Twenty-five microliters of ¹²⁵I-IP-10 was added to a final concentration of 0.100 nM. Lastly, 25 μl of cells at a density of 1×10⁶ cells per well were added and the plates were incubated on a plate shaker for 60 minutes at room temperature, washed and counted as described above. EC₅₀ values were calculated using Prism software. K_(i) values (in nM) were determined using the formula:

$K_{i} = \frac{{EC}_{50}}{1 + {\lbrack L\rbrack/K_{D}}}$ The results are summarized below in Table 6:

TABLE 6 Inhibition of IP-10 Binding to CXCR3 Clone ID Ki (nM) 10A12 0.09 10A12S 0.06 2G1 0.09 8F6 0.16 1E1 0.29 6B10 0.30 7C10 0.41 6A5 0.67 6A5 Batch 2 0.35 1D4 0.86

Example 5: Inhibition of IP-10 Induced Calcium Flux

In this example, the ability of anti-IP-10 antibodies to inhibit IP-10-induced calcium flux was examined using either 300.19 cells transfected to express CXCR3 or anti-CD3 activated human peripheral blood lymphocytes (PBLs) that express CXCR3. To prepare the PBLs, normal human blood was purified by standard Ficoll separation. The purified human PBLs were stimulated by adding the cells to plates coated with 3 μg/ml of anti-CD3 antibody and grown in RPMI with 10% FBS. Following a three day incubation, the cells were maintained in growth media containing 500 U/ml of IL-2. On the day of the study, the cells were washed and resuspended in media at a density of 2.5×10⁷ cells/ml. The 300.19 cells transfected to express CXCR3 were grown in RPMI containing 10% FBS. The 300.19 cells were resuspended in growth media at 2×10⁶ cells/ml.

To perform the assay, 100 μl of cell suspension was added to a black-sided, clear-bottomed 96 well plate which was coated with Poly-D-Lysine (Corning/Costar, cat. #3667). 100 microliters of Calcium 3 kit loading dye (FlexStation™, Molecular Devices, Inc., Sunnyvale, Calif.) was added to each well, the plates were spun at 1100 RPM for 4 minutes and incubated at 37° C. for 30 minutes. Using a 96-well reagent plate, human IP-10 (Peprotech, cat. #300-12) was diluted in Hank's Balanced Salt Solution with 20 mM HEPES and 1% FBS (800 pM for 300.19 cells and 1200 pM for human PBLs). Antibodies were serially diluted in the reagent plates containing IP-10. Control wells containing buffer alone or IP-10 alone were included. Twenty-two microliters of IP-10/antibody solution were added per well to the plates containing the dye labeled cells and calcium flux was determined by monitoring Calcium 3 fluorescence using the FlexStation™ instrument according to the manufacturer's instructions, over a time period of 200 seconds. The area under the curve (AUC) was calculated by the integration of the calcium flux between 20-100 seconds according to standard protocols (see e.g., Smart D. et al. (1999) Br. J. Pharmacol. 128:1-3). The data were analyzed using Prism™ software (Molecular Devices, Inc.) and IC₅₀ values (in nM) were determined The results are summarized below in Table 7:

TABLE 7 Inhibition of IP-10-Induced Calcium Flux Clone ID IC₅₀ (nM) for HPBL IC₅₀ (nM) for 300.19 Cells 10A12 1.25 0.18 10A12S 2.31 0.08 2G1 2.98 0.50 8F6 6.27 0.30 1E1 3.64 NT 6B10 4.40 0.50 7C10 8.15 0.77 6A5 2.85 0.61 6A5 Batch 2 2.18 0.42 1D4 4.07 0.34

Example 6: Inhibition of IP-10 Induced Cell Migration

The ability of anti-IP-10 antibodies to inhibit cell migration induced by IP-10 was examined in an in vitro chemotaxis assay. In a these experiments, CXCR3-expressing 300.19 cells were used and were stimulated with either: (i) 100 ng/ml of recombinant human IP-10 (rhIP-10); (ii) supernatant of THP-1 cells stimulated with IFN gamma (which induces secretion of native IP-10 and MIG), wherein THP-1 derived IP-10 was at a concentration of 16 ng/ml and MIG activity was blocked by addition of anti-MIG (R&D Systems) at 2.5 μg/ml; or (iii) 100 ng/ml recombinant rhesus macaque IP-10 (rrmIP-10). Inhibition of cell migration was assessed using various concentrations of antibodies and a chemotactic index was determined

Specifically, chemotaxis inhibition was assessed using a standard 96 well plate assay (Multiscreen MIC plates (Millipore)). A 5 μm filter was used for transfected cell lines; and 3 μm filter was used for primary cells. Responding cells (300.19 CXCR3+; MBP-specific human PBMC cells) were resuspended in chemotaxis buffer (RPMI+1% BSA or FBS) at 1×10⁶ cells/ml. 100 μl of cell suspension was added to the upper well and left to incubate for 30 minutes at 37° C. 5% CO₂ was applied prior to addition to the bottom well.

Human and rhesus macaque IP-10 was prepared at 100 ng/ml; for THP-1 derived IP-10, THP-1 cells were stimulated with IFN-γ (0.2 ng/ml) and supernatant was collected; MS CSF derived IP-10 was used neat. Ligand was prepared in 150 μL of chemotaxis buffer and placed in the lower chamber.

For chemotaxis inhibition assays, ligand was pre-incubated with varying concentrations of the indicated anti-IP-10 antibody (5 μg/ml, 2.5 μg/ml, 1.25 μg/ml, 0.613 μg/ml, 0.3 μg/ml, 0.015n/ml) for 30 minutes at 37° C. in 5% CO2 prior to assay. The top chamber was placed over wells, and the wells were incubated for 2 hours at 37° C. in 5% CO2. At the end of the incubation, responding cells were aspirated from the top chamber. The top chamber was carefully removed. Cells were counted in 4 random fields/well at 400× magnification. Data was averaged across three wells and presented as a chemotaxis index (i.e. the fold migration in response to ligand over media alone).

The results, expressed as IC₅₀ values, are summarized below in Table 8:

TABLE 8 Inhibition of IP-10 Induced Cell Migration rhIP-10 THP-1 IP-10 rrmIP-10 Clone ID IC₅₀ (μg/ml) IC₅₀ (μg/ml) IC₅₀ (μg/ml) 6A5 (Batch 2) 0.156 0.132 0.119 8F6 0.355 0.173 0.100 6B10 1.1 0.193 0.149 10A12S 0.115 0.211 15.1 1D4 0.156 0.247 0.163

The ability of anti-IP-10 antibodies to inhibit CXCR3-expressing 300.19 cell migration in response to cerebrospinal fluid (CSF) from multiple sclerosis (MS) patients was also examined Again, anti-MIG antibody at 2.5 μg/ml was added to the CSF sample to neutralize MIG activity. The results from two experiments, expressed as IC₅₀ values, are summarized below in Table 9:

TABLE 9 Inhibition of MS-CSF Induced Cell Migration Expt. 1 Expt. 2 Clone ID IC₅₀ (μg/ml) IC₅₀ (μg/ml) 6A5 (Batch 2) 0.100 0.236 10A12S 0.562 0.577

Cell migration studies were also performed using CXCR3-expressing 300.19 cells and recombinant human MIG (R&D Systems), at 200 ng/ml, to examine the ability of the anti-IP-10 antibodies to inhibit MIG-induced cell migration. The anti-IP-10 antibodies 6B10, 8F6, 1D4, 6A5 batch 2, 10A12 and 10A12S were individually tested at 1 μg/ml and were found not to inhibit the MIG-induced cell migration.

Example 7: Binding of Antibodies to Brain Section of MS Patients

In this example, the ability of anti-IP-10 antibodies to stain brain sections from a multiple sclerosis (MS) patient was examined Brain sections from a 57 year old female MS patient were obtained 19.8 hours post-mortem and showed an irregular shaped periventricular plaque (1.3 cm×1.0 cm) with numerous additional smaller plaques present throughout the remaining white matter. LFB staining showed complete demyelination Immunohistochemistry was performed on the sections using the 6A5 (batch 2) and 10A12S anti-IP-10 antibodies, as well as anti-GFAP and anti-CD68, as positive controls, and a negative control antibody.

A standard immunohistochemistry protocol was employed for anti-IP-10 staining of the sections. Sections were blocked using 2%-10% serum. 100 μl/section primary antibody (e.g., 6A5) diluted 1:100 in 2% serum was added, then incubated 1 hr at RT. Optionally, sections were incubated overnight at 4° C. and washed. The secondary anti-human biotinylated antibody (diluted in 2% serum (100 μl/section)) was then added and incubated 30-60 minutes at RT. Endogenous peroxidases were removed by adding dilute H₂O₂ in MeOH. Next, ABC Solution (Vector Labs) was added, 100 μl/section, and incubated for 30 mins RT. DAB substrate solution was prepared immediately prior to use. 100 μl per section was applied to slides before incubating in the dark for 10-20 mins (as necessary for development). Slides were then counterstained with Hematoxylin nuclear stain for 3 min (Progress checked after 1 min). Finally slides were incubate in 2% sodium bicarbonate for 45 seconds to bring out the colour.

The results showed that both 6A5 and 10A12S could bind to IP-10 in situ in the brain sections of the MS patient, with 6A5 staining being more intense than 10A12S staining.

Example 8: Construction of HCo17 Strain of Transgenic Mice

The HCo17 transgenic mouse strain was generated by coinjection of the 80 kb insert of pHC2 (Taylor et al. (1994) Int. Immunol., 6: 579-591), the 25 Kb insert of pVX6, and a ˜460 kb yeast artificial chromosome fragment of the yIgH24 chromosome. The pHC2 construct alone is fully capable of being rearranged in vivo to form functional human heavy chain immunoglobulin loci; pVX6 and yIgH24 were added to contribute additional germline V_(H) diversity. The individual components of the DNA mixture used to produce HCo17 are described below.

The pHC2 insert described above contains four functional human germline V_(H) gene segments: 1-69 (DP-10), 5-51 (DP-73), 4-34 (DP-63), and 3-30.3 (DP-46). In addition, this construct also contains human genomic sequences comprising 15 functional D segments, all 6 J segments, as well as μ and γ1 constant region segments and a functional μ-γ1 switch region.

The pVX6 insert contains 3 human germline VH segments, VH1-18 (DP-14), VH5-51 (DP-73) and VH3-23 (DP-47). An 8.5 kb HindIII/SalI DNA fragment, comprising the germline human VH1-18 (DP-14) gene, together with approximately 2.5 kb of 5′ flanking, and 5 kb of 3′ flanking genomic sequence, was subcloned into the plasmid vector pSP72 (Promega, Madison, Wis.) to generate the plasmid p343.7.16. A 7 kb BamHI/HindIII DNA fragment, comprising the germline human VH5-51 (DP-73) gene, together with approximately 5 kb of 5′ flanking and 1 kb of 3′ flanking genomic sequence, was cloned into the pBR322 based plasmid cloning vector pGP1f (Taylor et al. (1992) Nucleic Acids Res. 20: 6287-6295), to generate the plasmid p251f. A new cloning vector derived from pGP1f, pGP1k, was digested with EcoRV/BamHI, and ligated to a 10 kb EcoRV/BamHI DNA fragment, comprising the germline human VH3-23 (DP47) gene, together with approximately 4 kb of 5′ flanking and 5 kb of 3′ flanking genomic sequence. The resulting plasmid, p112.2RR.7, was digested with BamHI/SalI and ligated with the 7 kb purified BamHI/SalI insert of p251f. The resulting plasmid, pVx4, was digested with XhoI and ligated with the 8.5 kb XhoI/SalI insert of p343.7.16. A clone was obtained with the VH1-18 gene in the same orientation as the other two V genes. This clone, designated pVx6, was then digested with NotI for insert preparation.

The yeast artificial chromosome (YAC) yIgH24 was originally identified by PCR screening using VH3 and VH4 family specific primers and is mapped to the human chromosome 14 by VH content. It was established that yIgH24 contains VH segments including members of the VH families VH1, VH2, VH3, VH4, and VH5, and in particular at least VH1-24, VH1-45, VH1-46, VH2-26, VH3-30, V 3-30.5, VH3-30.3, VH3-33, VH3-43, VH3-48, VH3-49, VH3-53, VH4-28, VH4-30, VH4-30.4, VH4-30.3, VH4-31, VH4-34, 4-39, and VH5-51.

Purified inserts from pVX6 (26 kb), pHC2 (80 kb), and yIgH24 (˜460 kb) were combined in a 1:1:1 molar ratio, and microinjected into the pronuclei of one-half day (C57BL/6J×DBA/2J) F2 embryos as described by Hogan et al. (B. Hogan et al., Manipulating the Mouse Embryo, A Laboratory Manual, 2^(nd) edition, 1994, Cold Spring Harbor Laboratory Press, Plainview, N.Y.). A founder line of transgenic mice, comprising sequences from pVx6, HC2 and yIgH24, was established from mice that developed from the injected embryos. This line was designated (HCo17) 25950.

The (HCo17) 25950 line was then bred with mice comprising the CMD mutation (described in Example 1 of PCT Publication WO 01/09187), the JKD mutation (Chen et al. (1993) EMBO J. 12: 811-820), and the (KCo5) 9272 transgene (Fishwild et al. (1996) Nature Biotechnology 14: 845-851). The resulting mice express human immunoglobulin heavy and kappa light chain transgenes in a background homozygous for disruption of the endogenous mouse heavy and kappa light chain loci.

SUMMARY OF SEQUENCE LISTING

SEQ ID NO: SEQUENCE 1 VH CDR1 a.a. 1D4 2 VH CDR1 a.a. 1E1 3 VH CDR1 a.a. 2G1 4 VH CDR1 a.a. 3C4 5 VH CDR1 a.a. 6A5 6 VH CDR1 a.a. 6A8 7 VH CDR1 a.a. 6B10 8 VH CDR1 a.a. 7C10 9 VH CDR1 a.a. 8F6 10 VH CDR1 a.a. 10A12 11 VH CDR1 a.a. 10A12S 12 VH CDR1 a.a. 13C4 13 VH CDR2 a.a. 1D4 14 VH CDR2 a.a. 1E1 15 VH CDR2 a.a. 2G1 16 VH CDR2 a.a. 3C4 17 VH CDR2 a.a. 6A5 18 VH CDR2 a.a. 6A8 19 VH CDR2 a.a. 6B10 20 VH CDR2 a.a. 7C10 21 VH CDR2 a.a. 8F6 22 VH CDR2 a.a. 10A12 23 VH CDR2 a.a. 13C4 24 VH CDR3 a.a. 1D4 25 VH CDR3 a.a. 1E1 26 VH CDR3 a.a. 2G1 27 VH CDR3 a.a. 3C4 28 VH CDR3 a.a. 6A5 29 VH CDR3 a.a. 6A8 30 VH CDR3 a.a. 6B10 31 VH CDR3 a.a. 7C10 32 VH CDR3 a.a. 8F6 33 VH CDR3 a.a. 10A12 34 VH CDR3 a.a. 13C4 35 VH a.a. 1D4 36 VH a.a. 1E1 37 VH a.a. 2G1 38 VH a.a. 3C4 39 VH a.a. 6A5 40 VH a.a. 6A8 41 VH a.a. 6B10 42 VH a.a. 7C10 43 VH a.a. 8F6 44 VH a.a. 10A12 45 VH a.a. 10A12S 46 VH a.a. 13C4 47 VH 3-33 germline a.a. 48 VH 3-30.3 germline a.a. 49 VH 5-51 germline a.a. 50 VH 4-61 germline a.a. 51 Vk CDR1 a.a. 1D4 52 Vk CDR1 a.a. 1E1 53 Vk CDR1 a.a. 2G1 54 Vk CDR1 a.a. 3C4 55 Vk CDR1 a.a. 6A5 56 Vk CDR1 a.a. 6A8 57 Vk CDR1 a.a. 6B10 58 Vk CDR1 a.a. 7C10 59 Vk CDR1 a.a. 8F6 60 Vk CDR1 a.a. 10A12 61 Vk CDR1 a.a. 13C4 62 Vk CDR2 a.a. 1D4 63 Vk CDR2 a.a. 1E1 64 Vk CDR2 a.a. 2G1 65 Vk CDR2 a.a. 3C4 66 Vk CDR2 a.a. 6A5 67 Vk CDR2 a.a. 6A8 68 Vk CDR2 a.a. 6B10 69 Vk CDR2 a.a. 7C10 70 Vk CDR2 a.a. 8F6 71 Vk CDR2 a.a. 10A12 72 Vk CDR2 a.a. 13C4 73 Vk CDR3 a.a. 1D4 74 Vk CDR3 a.a. 1E1 75 Vk CDR3 a.a. 2G1 76 Vk CDR3 a.a. 3C4 77 Vk CDR3 a.a. 6A5 78 Vk CDR3 a.a. 6A8 79 Vk CDR3 a.a. 6B10 80 Vk CDR3 a.a. 7C10 81 Vk CDR3 a.a. 8F6 82 Vk CDR3 a.a. 10A12 83 Vk CDR3 a.a. 13C4 84 Vk a.a. 1D4 85 Vk a.a. 1E1 86 Vk a.a. 2G1 87 Vk a.a. 3C4 88 Vk a.a. 6A5 89 Vk a.a. 6A8 90 Vk a.a. 6B10 91 Vk a.a. 7C10 92 Vk a.a. 8F6 93 Vk a.a. 10A12 94 Vk a.a. 13C4 95 Vk A27 germline a.a. 96 Vk L6 germline a.a. 97 Vk L18 germline a.a. 98 Vk L15 germline a.a. 99 VH n.t. 1D4 100 VH n.t. 1E1 101 VH n.t. 2G1 102 VH n.t. 3C4 103 VH n.t. 6A5 104 VH n.t. 6A8 105 VH n.t. 6B10 106 VH n.t. 7C10 107 VH n.t. 8F6 108 VH n.t. 10A12 109 VH n.t. 13C4 110 Vk n.t 1D4 111 Vk n.t. 1E1 112 Vk n.t. 2G1 113 Vk n.t. 3C4 114 Vk n.t. 6A5 115 Vk n.t. 6A8 116 Vk n.t. 6B10 117 Vk n.t. 7C10 118 Vk n.t. 8F6 119 Vk n.t. 10A12 120 Vk n.t 13C4 121 Human IP-10 a.a. 122 Human CXCR3 a.a. 123 Rhesus monkey IP-10 a.a. 124 Mouse IP-10 a.a. 125 Human Mig a.a. 126 Human ITAC a.a.

EQUIVALENTS

Those skilled in the art will recognize or be able to ascertain, using no more than routine experimentation, many equivalents of the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims. 

We claim:
 1. An isolated nucleic acid molecule which encodes the heavy and light chain variable regions of an antibody that binds to human IP-10 (SEQ ID NO: 121), wherein the light chain variable region comprises the amino acid sequence set forth in SEQ ID NO: 88 or is encoded by the nucleotide sequence set forth in SEQ ID NO:
 114. 2. An expression vector comprising the nucleic acid molecule of claim
 1. 3. A host cell comprising the expression vector of claim
 2. 4. A host cell comprising one or more nucleic acid molecules encoding the heavy and light chain variable regions of an antibody which binds to human IP-10, wherein the light chain variable region comprises the amino acid sequence set forth in SEQ ID NO: 88 or is encoded by the nucleotide sequence set forth in SEQ ID NO:
 114. 